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llmeval-env/lib/python3.10/site-packages/scipy/optimize/_trustregion_constr/tests/test_projections.py

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+import numpy as np
+import scipy.linalg
+from scipy.sparse import csc_matrix
+from scipy.optimize._trustregion_constr.projections \
+    import projections, orthogonality
+from numpy.testing import (TestCase, assert_array_almost_equal,
+                           assert_equal, assert_allclose)
+
+try:
+    from sksparse.cholmod import cholesky_AAt  # noqa: F401
+    sksparse_available = True
+    available_sparse_methods = ("NormalEquation", "AugmentedSystem")
+except ImportError:
+    sksparse_available = False
+    available_sparse_methods = ("AugmentedSystem",)
+available_dense_methods = ('QRFactorization', 'SVDFactorization')
+
+
+class TestProjections(TestCase):
+
+    def test_nullspace_and_least_squares_sparse(self):
+        A_dense = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                            [0, 8, 7, 0, 1, 5, 9, 0],
+                            [1, 0, 0, 0, 0, 1, 2, 3]])
+        At_dense = A_dense.T
+        A = csc_matrix(A_dense)
+        test_points = ([1, 2, 3, 4, 5, 6, 7, 8],
+                       [1, 10, 3, 0, 1, 6, 7, 8],
+                       [1.12, 10, 0, 0, 100000, 6, 0.7, 8])
+
+        for method in available_sparse_methods:
+            Z, LS, _ = projections(A, method)
+            for z in test_points:
+                # Test if x is in the null_space
+                x = Z.matvec(z)
+                assert_array_almost_equal(A.dot(x), 0)
+                # Test orthogonality
+                assert_array_almost_equal(orthogonality(A, x), 0)
+                # Test if x is the least square solution
+                x = LS.matvec(z)
+                x2 = scipy.linalg.lstsq(At_dense, z)[0]
+                assert_array_almost_equal(x, x2)
+
+    def test_iterative_refinements_sparse(self):
+        A_dense = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                            [0, 8, 7, 0, 1, 5, 9, 0],
+                            [1, 0, 0, 0, 0, 1, 2, 3]])
+        A = csc_matrix(A_dense)
+        test_points = ([1, 2, 3, 4, 5, 6, 7, 8],
+                       [1, 10, 3, 0, 1, 6, 7, 8],
+                       [1.12, 10, 0, 0, 100000, 6, 0.7, 8],
+                       [1, 0, 0, 0, 0, 1, 2, 3+1e-10])
+
+        for method in available_sparse_methods:
+            Z, LS, _ = projections(A, method, orth_tol=1e-18, max_refin=100)
+            for z in test_points:
+                # Test if x is in the null_space
+                x = Z.matvec(z)
+                atol = 1e-13 * abs(x).max()
+                assert_allclose(A.dot(x), 0, atol=atol)
+                # Test orthogonality
+                assert_allclose(orthogonality(A, x), 0, atol=1e-13)
+
+    def test_rowspace_sparse(self):
+        A_dense = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                            [0, 8, 7, 0, 1, 5, 9, 0],
+                            [1, 0, 0, 0, 0, 1, 2, 3]])
+        A = csc_matrix(A_dense)
+        test_points = ([1, 2, 3],
+                       [1, 10, 3],
+                       [1.12, 10, 0])
+
+        for method in available_sparse_methods:
+            _, _, Y = projections(A, method)
+            for z in test_points:
+                # Test if x is solution of A x = z
+                x = Y.matvec(z)
+                assert_array_almost_equal(A.dot(x), z)
+                # Test if x is in the return row space of A
+                A_ext = np.vstack((A_dense, x))
+                assert_equal(np.linalg.matrix_rank(A_dense),
+                             np.linalg.matrix_rank(A_ext))
+
+    def test_nullspace_and_least_squares_dense(self):
+        A = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                      [0, 8, 7, 0, 1, 5, 9, 0],
+                      [1, 0, 0, 0, 0, 1, 2, 3]])
+        At = A.T
+        test_points = ([1, 2, 3, 4, 5, 6, 7, 8],
+                       [1, 10, 3, 0, 1, 6, 7, 8],
+                       [1.12, 10, 0, 0, 100000, 6, 0.7, 8])
+
+        for method in available_dense_methods:
+            Z, LS, _ = projections(A, method)
+            for z in test_points:
+                # Test if x is in the null_space
+                x = Z.matvec(z)
+                assert_array_almost_equal(A.dot(x), 0)
+                # Test orthogonality
+                assert_array_almost_equal(orthogonality(A, x), 0)
+                # Test if x is the least square solution
+                x = LS.matvec(z)
+                x2 = scipy.linalg.lstsq(At, z)[0]
+                assert_array_almost_equal(x, x2)
+
+    def test_compare_dense_and_sparse(self):
+        D = np.diag(range(1, 101))
+        A = np.hstack([D, D, D, D])
+        A_sparse = csc_matrix(A)
+        np.random.seed(0)
+
+        Z, LS, Y = projections(A)
+        Z_sparse, LS_sparse, Y_sparse = projections(A_sparse)
+        for k in range(20):
+            z = np.random.normal(size=(400,))
+            assert_array_almost_equal(Z.dot(z), Z_sparse.dot(z))
+            assert_array_almost_equal(LS.dot(z), LS_sparse.dot(z))
+            x = np.random.normal(size=(100,))
+            assert_array_almost_equal(Y.dot(x), Y_sparse.dot(x))
+
+    def test_compare_dense_and_sparse2(self):
+        D1 = np.diag([-1.7, 1, 0.5])
+        D2 = np.diag([1, -0.6, -0.3])
+        D3 = np.diag([-0.3, -1.5, 2])
+        A = np.hstack([D1, D2, D3])
+        A_sparse = csc_matrix(A)
+        np.random.seed(0)
+
+        Z, LS, Y = projections(A)
+        Z_sparse, LS_sparse, Y_sparse = projections(A_sparse)
+        for k in range(1):
+            z = np.random.normal(size=(9,))
+            assert_array_almost_equal(Z.dot(z), Z_sparse.dot(z))
+            assert_array_almost_equal(LS.dot(z), LS_sparse.dot(z))
+            x = np.random.normal(size=(3,))
+            assert_array_almost_equal(Y.dot(x), Y_sparse.dot(x))
+
+    def test_iterative_refinements_dense(self):
+        A = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                            [0, 8, 7, 0, 1, 5, 9, 0],
+                            [1, 0, 0, 0, 0, 1, 2, 3]])
+        test_points = ([1, 2, 3, 4, 5, 6, 7, 8],
+                       [1, 10, 3, 0, 1, 6, 7, 8],
+                       [1, 0, 0, 0, 0, 1, 2, 3+1e-10])
+
+        for method in available_dense_methods:
+            Z, LS, _ = projections(A, method, orth_tol=1e-18, max_refin=10)
+            for z in test_points:
+                # Test if x is in the null_space
+                x = Z.matvec(z)
+                assert_allclose(A.dot(x), 0, rtol=0, atol=2.5e-14)
+                # Test orthogonality
+                assert_allclose(orthogonality(A, x), 0, rtol=0, atol=5e-16)
+
+    def test_rowspace_dense(self):
+        A = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                      [0, 8, 7, 0, 1, 5, 9, 0],
+                      [1, 0, 0, 0, 0, 1, 2, 3]])
+        test_points = ([1, 2, 3],
+                       [1, 10, 3],
+                       [1.12, 10, 0])
+
+        for method in available_dense_methods:
+            _, _, Y = projections(A, method)
+            for z in test_points:
+                # Test if x is solution of A x = z
+                x = Y.matvec(z)
+                assert_array_almost_equal(A.dot(x), z)
+                # Test if x is in the return row space of A
+                A_ext = np.vstack((A, x))
+                assert_equal(np.linalg.matrix_rank(A),
+                             np.linalg.matrix_rank(A_ext))
+
+
+class TestOrthogonality(TestCase):
+
+    def test_dense_matrix(self):
+        A = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                      [0, 8, 7, 0, 1, 5, 9, 0],
+                      [1, 0, 0, 0, 0, 1, 2, 3]])
+        test_vectors = ([-1.98931144, -1.56363389,
+                         -0.84115584, 2.2864762,
+                         5.599141, 0.09286976,
+                         1.37040802, -0.28145812],
+                        [697.92794044, -4091.65114008,
+                         -3327.42316335, 836.86906951,
+                         99434.98929065, -1285.37653682,
+                         -4109.21503806, 2935.29289083])
+        test_expected_orth = (0, 0)
+
+        for i in range(len(test_vectors)):
+            x = test_vectors[i]
+            orth = test_expected_orth[i]
+            assert_array_almost_equal(orthogonality(A, x), orth)
+
+    def test_sparse_matrix(self):
+        A = np.array([[1, 2, 3, 4, 0, 5, 0, 7],
+                      [0, 8, 7, 0, 1, 5, 9, 0],
+                      [1, 0, 0, 0, 0, 1, 2, 3]])
+        A = csc_matrix(A)
+        test_vectors = ([-1.98931144, -1.56363389,
+                         -0.84115584, 2.2864762,
+                         5.599141, 0.09286976,
+                         1.37040802, -0.28145812],
+                        [697.92794044, -4091.65114008,
+                         -3327.42316335, 836.86906951,
+                         99434.98929065, -1285.37653682,
+                         -4109.21503806, 2935.29289083])
+        test_expected_orth = (0, 0)
+
+        for i in range(len(test_vectors)):
+            x = test_vectors[i]
+            orth = test_expected_orth[i]
+            assert_array_almost_equal(orthogonality(A, x), orth)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/_trustregion_constr/tests/test_qp_subproblem.py

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+import numpy as np
+from scipy.sparse import csc_matrix
+from scipy.optimize._trustregion_constr.qp_subproblem \
+    import (eqp_kktfact,
+            projected_cg,
+            box_intersections,
+            sphere_intersections,
+            box_sphere_intersections,
+            modified_dogleg)
+from scipy.optimize._trustregion_constr.projections \
+    import projections
+from numpy.testing import TestCase, assert_array_almost_equal, assert_equal
+import pytest
+
+
+class TestEQPDirectFactorization(TestCase):
+
+    # From Example 16.2 Nocedal/Wright "Numerical
+    # Optimization" p.452.
+    def test_nocedal_example(self):
+        H = csc_matrix([[6, 2, 1],
+                        [2, 5, 2],
+                        [1, 2, 4]])
+        A = csc_matrix([[1, 0, 1],
+                        [0, 1, 1]])
+        c = np.array([-8, -3, -3])
+        b = -np.array([3, 0])
+        x, lagrange_multipliers = eqp_kktfact(H, c, A, b)
+        assert_array_almost_equal(x, [2, -1, 1])
+        assert_array_almost_equal(lagrange_multipliers, [3, -2])
+
+
+class TestSphericalBoundariesIntersections(TestCase):
+
+    def test_2d_sphere_constraints(self):
+        # Interior inicial point
+        ta, tb, intersect = sphere_intersections([0, 0],
+                                                 [1, 0], 0.5)
+        assert_array_almost_equal([ta, tb], [0, 0.5])
+        assert_equal(intersect, True)
+
+        # No intersection between line and circle
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [0, 1], 1)
+        assert_equal(intersect, False)
+
+        # Outside initial point pointing toward outside the circle
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [1, 0], 1)
+        assert_equal(intersect, False)
+
+        # Outside initial point pointing toward inside the circle
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [-1, 0], 1.5)
+        assert_array_almost_equal([ta, tb], [0.5, 1])
+        assert_equal(intersect, True)
+
+        # Initial point on the boundary
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [1, 0], 2)
+        assert_array_almost_equal([ta, tb], [0, 0])
+        assert_equal(intersect, True)
+
+    def test_2d_sphere_constraints_line_intersections(self):
+        # Interior initial point
+        ta, tb, intersect = sphere_intersections([0, 0],
+                                                 [1, 0], 0.5,
+                                                 entire_line=True)
+        assert_array_almost_equal([ta, tb], [-0.5, 0.5])
+        assert_equal(intersect, True)
+
+        # No intersection between line and circle
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [0, 1], 1,
+                                                 entire_line=True)
+        assert_equal(intersect, False)
+
+        # Outside initial point pointing toward outside the circle
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [1, 0], 1,
+                                                 entire_line=True)
+        assert_array_almost_equal([ta, tb], [-3, -1])
+        assert_equal(intersect, True)
+
+        # Outside initial point pointing toward inside the circle
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [-1, 0], 1.5,
+                                                 entire_line=True)
+        assert_array_almost_equal([ta, tb], [0.5, 3.5])
+        assert_equal(intersect, True)
+
+        # Initial point on the boundary
+        ta, tb, intersect = sphere_intersections([2, 0],
+                                                 [1, 0], 2,
+                                                 entire_line=True)
+        assert_array_almost_equal([ta, tb], [-4, 0])
+        assert_equal(intersect, True)
+
+
+class TestBoxBoundariesIntersections(TestCase):
+
+    def test_2d_box_constraints(self):
+        # Box constraint in the direction of vector d
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [1, 1], [3, 3])
+        assert_array_almost_equal([ta, tb], [0.5, 1])
+        assert_equal(intersect, True)
+
+        # Negative direction
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [1, -3], [3, -1])
+        assert_equal(intersect, False)
+
+        # Some constraints are absent (set to +/- inf)
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-np.inf, 1],
+                                              [np.inf, np.inf])
+        assert_array_almost_equal([ta, tb], [0.5, 1])
+        assert_equal(intersect, True)
+
+        # Intersect on the face of the box
+        ta, tb, intersect = box_intersections([1, 0], [0, 1],
+                                              [1, 1], [3, 3])
+        assert_array_almost_equal([ta, tb], [1, 1])
+        assert_equal(intersect, True)
+
+        # Interior initial point
+        ta, tb, intersect = box_intersections([0, 0], [4, 4],
+                                              [-2, -3], [3, 2])
+        assert_array_almost_equal([ta, tb], [0, 0.5])
+        assert_equal(intersect, True)
+
+        # No intersection between line and box constraints
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-3, -3], [-1, -1])
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-3, 3], [-1, 1])
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-3, -np.inf],
+                                              [-1, np.inf])
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([0, 0], [1, 100],
+                                              [1, 1], [3, 3])
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([0.99, 0], [0, 2],
+                                                         [1, 1], [3, 3])
+        assert_equal(intersect, False)
+
+        # Initial point on the boundary
+        ta, tb, intersect = box_intersections([2, 2], [0, 1],
+                                              [-2, -2], [2, 2])
+        assert_array_almost_equal([ta, tb], [0, 0])
+        assert_equal(intersect, True)
+
+    def test_2d_box_constraints_entire_line(self):
+        # Box constraint in the direction of vector d
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [1, 1], [3, 3],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [0.5, 1.5])
+        assert_equal(intersect, True)
+
+        # Negative direction
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [1, -3], [3, -1],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [-1.5, -0.5])
+        assert_equal(intersect, True)
+
+        # Some constraints are absent (set to +/- inf)
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-np.inf, 1],
+                                              [np.inf, np.inf],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [0.5, np.inf])
+        assert_equal(intersect, True)
+
+        # Intersect on the face of the box
+        ta, tb, intersect = box_intersections([1, 0], [0, 1],
+                                              [1, 1], [3, 3],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [1, 3])
+        assert_equal(intersect, True)
+
+        # Interior initial pointoint
+        ta, tb, intersect = box_intersections([0, 0], [4, 4],
+                                              [-2, -3], [3, 2],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [-0.5, 0.5])
+        assert_equal(intersect, True)
+
+        # No intersection between line and box constraints
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-3, -3], [-1, -1],
+                                              entire_line=True)
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-3, 3], [-1, 1],
+                                              entire_line=True)
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([2, 0], [0, 2],
+                                              [-3, -np.inf],
+                                              [-1, np.inf],
+                                              entire_line=True)
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([0, 0], [1, 100],
+                                              [1, 1], [3, 3],
+                                              entire_line=True)
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_intersections([0.99, 0], [0, 2],
+                                              [1, 1], [3, 3],
+                                              entire_line=True)
+        assert_equal(intersect, False)
+
+        # Initial point on the boundary
+        ta, tb, intersect = box_intersections([2, 2], [0, 1],
+                                              [-2, -2], [2, 2],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [-4, 0])
+        assert_equal(intersect, True)
+
+    def test_3d_box_constraints(self):
+        # Simple case
+        ta, tb, intersect = box_intersections([1, 1, 0], [0, 0, 1],
+                                              [1, 1, 1], [3, 3, 3])
+        assert_array_almost_equal([ta, tb], [1, 1])
+        assert_equal(intersect, True)
+
+        # Negative direction
+        ta, tb, intersect = box_intersections([1, 1, 0], [0, 0, -1],
+                                              [1, 1, 1], [3, 3, 3])
+        assert_equal(intersect, False)
+
+        # Interior point
+        ta, tb, intersect = box_intersections([2, 2, 2], [0, -1, 1],
+                                              [1, 1, 1], [3, 3, 3])
+        assert_array_almost_equal([ta, tb], [0, 1])
+        assert_equal(intersect, True)
+
+    def test_3d_box_constraints_entire_line(self):
+        # Simple case
+        ta, tb, intersect = box_intersections([1, 1, 0], [0, 0, 1],
+                                              [1, 1, 1], [3, 3, 3],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [1, 3])
+        assert_equal(intersect, True)
+
+        # Negative direction
+        ta, tb, intersect = box_intersections([1, 1, 0], [0, 0, -1],
+                                              [1, 1, 1], [3, 3, 3],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [-3, -1])
+        assert_equal(intersect, True)
+
+        # Interior point
+        ta, tb, intersect = box_intersections([2, 2, 2], [0, -1, 1],
+                                              [1, 1, 1], [3, 3, 3],
+                                              entire_line=True)
+        assert_array_almost_equal([ta, tb], [-1, 1])
+        assert_equal(intersect, True)
+
+
+class TestBoxSphereBoundariesIntersections(TestCase):
+
+    def test_2d_box_constraints(self):
+        # Both constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-2, 2],
+                                                     [-1, -2], [1, 2], 2,
+                                                     entire_line=False)
+        assert_array_almost_equal([ta, tb], [0, 0.5])
+        assert_equal(intersect, True)
+
+        # None of the constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-1, 1],
+                                                     [-1, -3], [1, 3], 10,
+                                                     entire_line=False)
+        assert_array_almost_equal([ta, tb], [0, 1])
+        assert_equal(intersect, True)
+
+        # Box constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-4, 4],
+                                                     [-1, -3], [1, 3], 10,
+                                                     entire_line=False)
+        assert_array_almost_equal([ta, tb], [0, 0.5])
+        assert_equal(intersect, True)
+
+        # Spherical constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-4, 4],
+                                                     [-1, -3], [1, 3], 2,
+                                                     entire_line=False)
+        assert_array_almost_equal([ta, tb], [0, 0.25])
+        assert_equal(intersect, True)
+
+        # Infeasible problems
+        ta, tb, intersect = box_sphere_intersections([2, 2], [-4, 4],
+                                                     [-1, -3], [1, 3], 2,
+                                                     entire_line=False)
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-4, 4],
+                                                     [2, 4], [2, 4], 2,
+                                                     entire_line=False)
+        assert_equal(intersect, False)
+
+    def test_2d_box_constraints_entire_line(self):
+        # Both constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-2, 2],
+                                                     [-1, -2], [1, 2], 2,
+                                                     entire_line=True)
+        assert_array_almost_equal([ta, tb], [0, 0.5])
+        assert_equal(intersect, True)
+
+        # None of the constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-1, 1],
+                                                     [-1, -3], [1, 3], 10,
+                                                     entire_line=True)
+        assert_array_almost_equal([ta, tb], [0, 2])
+        assert_equal(intersect, True)
+
+        # Box constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-4, 4],
+                                                     [-1, -3], [1, 3], 10,
+                                                     entire_line=True)
+        assert_array_almost_equal([ta, tb], [0, 0.5])
+        assert_equal(intersect, True)
+
+        # Spherical constraints are active
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-4, 4],
+                                                     [-1, -3], [1, 3], 2,
+                                                     entire_line=True)
+        assert_array_almost_equal([ta, tb], [0, 0.25])
+        assert_equal(intersect, True)
+
+        # Infeasible problems
+        ta, tb, intersect = box_sphere_intersections([2, 2], [-4, 4],
+                                                     [-1, -3], [1, 3], 2,
+                                                     entire_line=True)
+        assert_equal(intersect, False)
+        ta, tb, intersect = box_sphere_intersections([1, 1], [-4, 4],
+                                                     [2, 4], [2, 4], 2,
+                                                     entire_line=True)
+        assert_equal(intersect, False)
+
+
+class TestModifiedDogleg(TestCase):
+
+    def test_cauchypoint_equalsto_newtonpoint(self):
+        A = np.array([[1, 8]])
+        b = np.array([-16])
+        _, _, Y = projections(A)
+        newton_point = np.array([0.24615385, 1.96923077])
+
+        # Newton point inside boundaries
+        x = modified_dogleg(A, Y, b, 2, [-np.inf, -np.inf], [np.inf, np.inf])
+        assert_array_almost_equal(x, newton_point)
+
+        # Spherical constraint active
+        x = modified_dogleg(A, Y, b, 1, [-np.inf, -np.inf], [np.inf, np.inf])
+        assert_array_almost_equal(x, newton_point/np.linalg.norm(newton_point))
+
+        # Box constraints active
+        x = modified_dogleg(A, Y, b, 2, [-np.inf, -np.inf], [0.1, np.inf])
+        assert_array_almost_equal(x, (newton_point/newton_point[0]) * 0.1)
+
+    def test_3d_example(self):
+        A = np.array([[1, 8, 1],
+                      [4, 2, 2]])
+        b = np.array([-16, 2])
+        Z, LS, Y = projections(A)
+
+        newton_point = np.array([-1.37090909, 2.23272727, -0.49090909])
+        cauchy_point = np.array([0.11165723, 1.73068711, 0.16748585])
+        origin = np.zeros_like(newton_point)
+
+        # newton_point inside boundaries
+        x = modified_dogleg(A, Y, b, 3, [-np.inf, -np.inf, -np.inf],
+                            [np.inf, np.inf, np.inf])
+        assert_array_almost_equal(x, newton_point)
+
+        # line between cauchy_point and newton_point contains best point
+        # (spherical constraint is active).
+        x = modified_dogleg(A, Y, b, 2, [-np.inf, -np.inf, -np.inf],
+                            [np.inf, np.inf, np.inf])
+        z = cauchy_point
+        d = newton_point-cauchy_point
+        t = ((x-z)/(d))
+        assert_array_almost_equal(t, np.full(3, 0.40807330))
+        assert_array_almost_equal(np.linalg.norm(x), 2)
+
+        # line between cauchy_point and newton_point contains best point
+        # (box constraint is active).
+        x = modified_dogleg(A, Y, b, 5, [-1, -np.inf, -np.inf],
+                            [np.inf, np.inf, np.inf])
+        z = cauchy_point
+        d = newton_point-cauchy_point
+        t = ((x-z)/(d))
+        assert_array_almost_equal(t, np.full(3, 0.7498195))
+        assert_array_almost_equal(x[0], -1)
+
+        # line between origin and cauchy_point contains best point
+        # (spherical constraint is active).
+        x = modified_dogleg(A, Y, b, 1, [-np.inf, -np.inf, -np.inf],
+                            [np.inf, np.inf, np.inf])
+        z = origin
+        d = cauchy_point
+        t = ((x-z)/(d))
+        assert_array_almost_equal(t, np.full(3, 0.573936265))
+        assert_array_almost_equal(np.linalg.norm(x), 1)
+
+        # line between origin and newton_point contains best point
+        # (box constraint is active).
+        x = modified_dogleg(A, Y, b, 2, [-np.inf, -np.inf, -np.inf],
+                            [np.inf, 1, np.inf])
+        z = origin
+        d = newton_point
+        t = ((x-z)/(d))
+        assert_array_almost_equal(t, np.full(3, 0.4478827364))
+        assert_array_almost_equal(x[1], 1)
+
+
+class TestProjectCG(TestCase):
+
+    # From Example 16.2 Nocedal/Wright "Numerical
+    # Optimization" p.452.
+    def test_nocedal_example(self):
+        H = csc_matrix([[6, 2, 1],
+                        [2, 5, 2],
+                        [1, 2, 4]])
+        A = csc_matrix([[1, 0, 1],
+                        [0, 1, 1]])
+        c = np.array([-8, -3, -3])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b)
+        assert_equal(info["stop_cond"], 4)
+        assert_equal(info["hits_boundary"], False)
+        assert_array_almost_equal(x, [2, -1, 1])
+
+    def test_compare_with_direct_fact(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b, tol=0)
+        x_kkt, _ = eqp_kktfact(H, c, A, b)
+        assert_equal(info["stop_cond"], 1)
+        assert_equal(info["hits_boundary"], False)
+        assert_array_almost_equal(x, x_kkt)
+
+    def test_trust_region_infeasible(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        trust_radius = 1
+        Z, _, Y = projections(A)
+        with pytest.raises(ValueError):
+            projected_cg(H, c, Z, Y, b, trust_radius=trust_radius)
+
+    def test_trust_region_barely_feasible(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        trust_radius = 2.32379000772445021283
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               trust_radius=trust_radius)
+        assert_equal(info["stop_cond"], 2)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(np.linalg.norm(x), trust_radius)
+        assert_array_almost_equal(x, -Y.dot(b))
+
+    def test_hits_boundary(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        trust_radius = 3
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               trust_radius=trust_radius)
+        assert_equal(info["stop_cond"], 2)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(np.linalg.norm(x), trust_radius)
+
+    def test_negative_curvature_unconstrained(self):
+        H = csc_matrix([[1, 2, 1, 3],
+                        [2, 0, 2, 4],
+                        [1, 2, 0, 2],
+                        [3, 4, 2, 0]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 0, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        with pytest.raises(ValueError):
+            projected_cg(H, c, Z, Y, b, tol=0)
+
+    def test_negative_curvature(self):
+        H = csc_matrix([[1, 2, 1, 3],
+                        [2, 0, 2, 4],
+                        [1, 2, 0, 2],
+                        [3, 4, 2, 0]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 0, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        trust_radius = 1000
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               trust_radius=trust_radius)
+        assert_equal(info["stop_cond"], 3)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(np.linalg.norm(x), trust_radius)
+
+    # The box constraints are inactive at the solution but
+    # are active during the iterations.
+    def test_inactive_box_constraints(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               lb=[0.5, -np.inf,
+                                   -np.inf, -np.inf],
+                               return_all=True)
+        x_kkt, _ = eqp_kktfact(H, c, A, b)
+        assert_equal(info["stop_cond"], 1)
+        assert_equal(info["hits_boundary"], False)
+        assert_array_almost_equal(x, x_kkt)
+
+    # The box constraints active and the termination is
+    # by maximum iterations (infeasible interaction).
+    def test_active_box_constraints_maximum_iterations_reached(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               lb=[0.8, -np.inf,
+                                   -np.inf, -np.inf],
+                               return_all=True)
+        assert_equal(info["stop_cond"], 1)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(A.dot(x), -b)
+        assert_array_almost_equal(x[0], 0.8)
+
+    # The box constraints are active and the termination is
+    # because it hits boundary (without infeasible interaction).
+    def test_active_box_constraints_hits_boundaries(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        trust_radius = 3
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               ub=[np.inf, np.inf, 1.6, np.inf],
+                               trust_radius=trust_radius,
+                               return_all=True)
+        assert_equal(info["stop_cond"], 2)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(x[2], 1.6)
+
+    # The box constraints are active and the termination is
+    # because it hits boundary (infeasible interaction).
+    def test_active_box_constraints_hits_boundaries_infeasible_iter(self):
+        H = csc_matrix([[6, 2, 1, 3],
+                        [2, 5, 2, 4],
+                        [1, 2, 4, 5],
+                        [3, 4, 5, 7]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 1, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        trust_radius = 4
+        Z, _, Y = projections(A)
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               ub=[np.inf, 0.1, np.inf, np.inf],
+                               trust_radius=trust_radius,
+                               return_all=True)
+        assert_equal(info["stop_cond"], 2)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(x[1], 0.1)
+
+    # The box constraints are active and the termination is
+    # because it hits boundary (no infeasible interaction).
+    def test_active_box_constraints_negative_curvature(self):
+        H = csc_matrix([[1, 2, 1, 3],
+                        [2, 0, 2, 4],
+                        [1, 2, 0, 2],
+                        [3, 4, 2, 0]])
+        A = csc_matrix([[1, 0, 1, 0],
+                        [0, 1, 0, 1]])
+        c = np.array([-2, -3, -3, 1])
+        b = -np.array([3, 0])
+        Z, _, Y = projections(A)
+        trust_radius = 1000
+        x, info = projected_cg(H, c, Z, Y, b,
+                               tol=0,
+                               ub=[np.inf, np.inf, 100, np.inf],
+                               trust_radius=trust_radius)
+        assert_equal(info["stop_cond"], 3)
+        assert_equal(info["hits_boundary"], True)
+        assert_array_almost_equal(x[2], 100)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/_trustregion_constr/tests/test_report.py

@@ -0,0 +1,32 @@
+import numpy as np
+from scipy.optimize import minimize, Bounds
+
+def test_gh10880():
+    # checks that verbose reporting works with trust-constr for
+    # bound-contrained problems
+    bnds = Bounds(1, 2)
+    opts = {'maxiter': 1000, 'verbose': 2}
+    minimize(lambda x: x**2, x0=2., method='trust-constr',
+             bounds=bnds, options=opts)
+
+    opts = {'maxiter': 1000, 'verbose': 3}
+    minimize(lambda x: x**2, x0=2., method='trust-constr',
+             bounds=bnds, options=opts)
+
+def test_gh12922():
+    # checks that verbose reporting works with trust-constr for
+    # general constraints
+    def objective(x):
+        return np.array([(np.sum((x+1)**4))])
+
+    cons = {'type': 'ineq', 'fun': lambda x: -x[0]**2}
+    n = 25
+    x0 = np.linspace(-5, 5, n)
+
+    opts = {'maxiter': 1000, 'verbose': 2}
+    minimize(objective, x0=x0, method='trust-constr',
+                      constraints=cons, options=opts)
+
+    opts = {'maxiter': 1000, 'verbose': 3}
+    minimize(objective, x0=x0, method='trust-constr',
+                      constraints=cons, options=opts)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/cython_optimize/_zeros.pxd

@@ -0,0 +1,33 @@
+# Legacy public Cython API declarations
+#
+# NOTE: due to the way Cython ABI compatibility works, **no changes
+# should be made to this file** --- any API additions/changes should be
+# done in `cython_optimize.pxd` (see gh-11793).
+
+ctypedef double (*callback_type)(double, void*) noexcept
+
+ctypedef struct zeros_parameters:
+    callback_type function
+    void* args
+
+ctypedef struct zeros_full_output:
+    int funcalls
+    int iterations
+    int error_num
+    double root
+
+cdef double bisect(callback_type f, double xa, double xb, void* args,
+                   double xtol, double rtol, int iter,
+                   zeros_full_output *full_output) noexcept nogil
+
+cdef double ridder(callback_type f, double xa, double xb, void* args,
+                   double xtol, double rtol, int iter,
+                   zeros_full_output *full_output) noexcept nogil
+
+cdef double brenth(callback_type f, double xa, double xb, void* args,
+                   double xtol, double rtol, int iter,
+                   zeros_full_output *full_output) noexcept nogil
+
+cdef double brentq(callback_type f, double xa, double xb, void* args,
+                   double xtol, double rtol, int iter,
+                   zeros_full_output *full_output) noexcept nogil

llmeval-env/lib/python3.10/site-packages/scipy/optimize/cython_optimize/c_zeros.pxd

@@ -0,0 +1,26 @@
+cdef extern from "../Zeros/zeros.h":
+    ctypedef double (*callback_type)(double, void*) noexcept
+    ctypedef struct scipy_zeros_info:
+        int funcalls
+        int iterations
+        int error_num
+
+cdef extern from "../Zeros/bisect.c" nogil:
+    double bisect(callback_type f, double xa, double xb, double xtol,
+                  double rtol, int iter, void *func_data_param,
+                  scipy_zeros_info *solver_stats)
+
+cdef extern from "../Zeros/ridder.c" nogil:
+    double ridder(callback_type f, double xa, double xb, double xtol,
+                  double rtol, int iter, void *func_data_param,
+                  scipy_zeros_info *solver_stats)
+
+cdef extern from "../Zeros/brenth.c" nogil:
+    double brenth(callback_type f, double xa, double xb, double xtol,
+                  double rtol, int iter, void *func_data_param,
+                  scipy_zeros_info *solver_stats)
+
+cdef extern from "../Zeros/brentq.c" nogil:
+    double brentq(callback_type f, double xa, double xb, double xtol,
+                  double rtol, int iter, void *func_data_param,
+                  scipy_zeros_info *solver_stats)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__basinhopping.py

@@ -0,0 +1,525 @@
+"""
+Unit tests for the basin hopping global minimization algorithm.
+"""
+import copy
+
+from numpy.testing import (assert_almost_equal, assert_equal, assert_,
+                           assert_allclose)
+import pytest
+from pytest import raises as assert_raises
+import numpy as np
+from numpy import cos, sin
+
+from scipy.optimize import basinhopping, OptimizeResult
+from scipy.optimize._basinhopping import (
+    Storage, RandomDisplacement, Metropolis, AdaptiveStepsize)
+
+
+def func1d(x):
+    f = cos(14.5 * x - 0.3) + (x + 0.2) * x
+    df = np.array(-14.5 * sin(14.5 * x - 0.3) + 2. * x + 0.2)
+    return f, df
+
+
+def func2d_nograd(x):
+    f = cos(14.5 * x[0] - 0.3) + (x[1] + 0.2) * x[1] + (x[0] + 0.2) * x[0]
+    return f
+
+
+def func2d(x):
+    f = cos(14.5 * x[0] - 0.3) + (x[1] + 0.2) * x[1] + (x[0] + 0.2) * x[0]
+    df = np.zeros(2)
+    df[0] = -14.5 * sin(14.5 * x[0] - 0.3) + 2. * x[0] + 0.2
+    df[1] = 2. * x[1] + 0.2
+    return f, df
+
+
+def func2d_easyderiv(x):
+    f = 2.0*x[0]**2 + 2.0*x[0]*x[1] + 2.0*x[1]**2 - 6.0*x[0]
+    df = np.zeros(2)
+    df[0] = 4.0*x[0] + 2.0*x[1] - 6.0
+    df[1] = 2.0*x[0] + 4.0*x[1]
+
+    return f, df
+
+
+class MyTakeStep1(RandomDisplacement):
+    """use a copy of displace, but have it set a special parameter to
+    make sure it's actually being used."""
+    def __init__(self):
+        self.been_called = False
+        super().__init__()
+
+    def __call__(self, x):
+        self.been_called = True
+        return super().__call__(x)
+
+
+def myTakeStep2(x):
+    """redo RandomDisplacement in function form without the attribute stepsize
+    to make sure everything still works ok
+    """
+    s = 0.5
+    x += np.random.uniform(-s, s, np.shape(x))
+    return x
+
+
+class MyAcceptTest:
+    """pass a custom accept test
+
+    This does nothing but make sure it's being used and ensure all the
+    possible return values are accepted
+    """
+    def __init__(self):
+        self.been_called = False
+        self.ncalls = 0
+        self.testres = [False, 'force accept', True, np.bool_(True),
+                        np.bool_(False), [], {}, 0, 1]
+
+    def __call__(self, **kwargs):
+        self.been_called = True
+        self.ncalls += 1
+        if self.ncalls - 1 < len(self.testres):
+            return self.testres[self.ncalls - 1]
+        else:
+            return True
+
+
+class MyCallBack:
+    """pass a custom callback function
+
+    This makes sure it's being used. It also returns True after 10
+    steps to ensure that it's stopping early.
+
+    """
+    def __init__(self):
+        self.been_called = False
+        self.ncalls = 0
+
+    def __call__(self, x, f, accepted):
+        self.been_called = True
+        self.ncalls += 1
+        if self.ncalls == 10:
+            return True
+
+
+class TestBasinHopping:
+
+    def setup_method(self):
+        """ Tests setup.
+
+        Run tests based on the 1-D and 2-D functions described above.
+        """
+        self.x0 = (1.0, [1.0, 1.0])
+        self.sol = (-0.195, np.array([-0.195, -0.1]))
+
+        self.tol = 3  # number of decimal places
+
+        self.niter = 100
+        self.disp = False
+
+        # fix random seed
+        np.random.seed(1234)
+
+        self.kwargs = {"method": "L-BFGS-B", "jac": True}
+        self.kwargs_nograd = {"method": "L-BFGS-B"}
+
+    def test_TypeError(self):
+        # test the TypeErrors are raised on bad input
+        i = 1
+        # if take_step is passed, it must be callable
+        assert_raises(TypeError, basinhopping, func2d, self.x0[i],
+                      take_step=1)
+        # if accept_test is passed, it must be callable
+        assert_raises(TypeError, basinhopping, func2d, self.x0[i],
+                      accept_test=1)
+
+    def test_input_validation(self):
+        msg = 'target_accept_rate has to be in range \\(0, 1\\)'
+        with assert_raises(ValueError, match=msg):
+            basinhopping(func1d, self.x0[0], target_accept_rate=0.)
+        with assert_raises(ValueError, match=msg):
+            basinhopping(func1d, self.x0[0], target_accept_rate=1.)
+
+        msg = 'stepwise_factor has to be in range \\(0, 1\\)'
+        with assert_raises(ValueError, match=msg):
+            basinhopping(func1d, self.x0[0], stepwise_factor=0.)
+        with assert_raises(ValueError, match=msg):
+            basinhopping(func1d, self.x0[0], stepwise_factor=1.)
+
+    def test_1d_grad(self):
+        # test 1-D minimizations with gradient
+        i = 0
+        res = basinhopping(func1d, self.x0[i], minimizer_kwargs=self.kwargs,
+                           niter=self.niter, disp=self.disp)
+        assert_almost_equal(res.x, self.sol[i], self.tol)
+
+    def test_2d(self):
+        # test 2d minimizations with gradient
+        i = 1
+        res = basinhopping(func2d, self.x0[i], minimizer_kwargs=self.kwargs,
+                           niter=self.niter, disp=self.disp)
+        assert_almost_equal(res.x, self.sol[i], self.tol)
+        assert_(res.nfev > 0)
+
+    def test_njev(self):
+        # test njev is returned correctly
+        i = 1
+        minimizer_kwargs = self.kwargs.copy()
+        # L-BFGS-B doesn't use njev, but BFGS does
+        minimizer_kwargs["method"] = "BFGS"
+        res = basinhopping(func2d, self.x0[i],
+                           minimizer_kwargs=minimizer_kwargs, niter=self.niter,
+                           disp=self.disp)
+        assert_(res.nfev > 0)
+        assert_equal(res.nfev, res.njev)
+
+    def test_jac(self):
+        # test Jacobian returned
+        minimizer_kwargs = self.kwargs.copy()
+        # BFGS returns a Jacobian
+        minimizer_kwargs["method"] = "BFGS"
+
+        res = basinhopping(func2d_easyderiv, [0.0, 0.0],
+                           minimizer_kwargs=minimizer_kwargs, niter=self.niter,
+                           disp=self.disp)
+
+        assert_(hasattr(res.lowest_optimization_result, "jac"))
+
+        # in this case, the Jacobian is just [df/dx, df/dy]
+        _, jacobian = func2d_easyderiv(res.x)
+        assert_almost_equal(res.lowest_optimization_result.jac, jacobian,
+                            self.tol)
+
+    def test_2d_nograd(self):
+        # test 2-D minimizations without gradient
+        i = 1
+        res = basinhopping(func2d_nograd, self.x0[i],
+                           minimizer_kwargs=self.kwargs_nograd,
+                           niter=self.niter, disp=self.disp)
+        assert_almost_equal(res.x, self.sol[i], self.tol)
+
+    def test_all_minimizers(self):
+        # Test 2-D minimizations with gradient. Nelder-Mead, Powell, and COBYLA
+        # don't accept jac=True, so aren't included here.
+        i = 1
+        methods = ['CG', 'BFGS', 'Newton-CG', 'L-BFGS-B', 'TNC', 'SLSQP']
+        minimizer_kwargs = copy.copy(self.kwargs)
+        for method in methods:
+            minimizer_kwargs["method"] = method
+            res = basinhopping(func2d, self.x0[i],
+                               minimizer_kwargs=minimizer_kwargs,
+                               niter=self.niter, disp=self.disp)
+            assert_almost_equal(res.x, self.sol[i], self.tol)
+
+    def test_all_nograd_minimizers(self):
+        # Test 2-D minimizations without gradient. Newton-CG requires jac=True,
+        # so not included here.
+        i = 1
+        methods = ['CG', 'BFGS', 'L-BFGS-B', 'TNC', 'SLSQP',
+                   'Nelder-Mead', 'Powell', 'COBYLA']
+        minimizer_kwargs = copy.copy(self.kwargs_nograd)
+        for method in methods:
+            minimizer_kwargs["method"] = method
+            res = basinhopping(func2d_nograd, self.x0[i],
+                               minimizer_kwargs=minimizer_kwargs,
+                               niter=self.niter, disp=self.disp)
+            tol = self.tol
+            if method == 'COBYLA':
+                tol = 2
+            assert_almost_equal(res.x, self.sol[i], decimal=tol)
+
+    def test_pass_takestep(self):
+        # test that passing a custom takestep works
+        # also test that the stepsize is being adjusted
+        takestep = MyTakeStep1()
+        initial_step_size = takestep.stepsize
+        i = 1
+        res = basinhopping(func2d, self.x0[i], minimizer_kwargs=self.kwargs,
+                           niter=self.niter, disp=self.disp,
+                           take_step=takestep)
+        assert_almost_equal(res.x, self.sol[i], self.tol)
+        assert_(takestep.been_called)
+        # make sure that the build in adaptive step size has been used
+        assert_(initial_step_size != takestep.stepsize)
+
+    def test_pass_simple_takestep(self):
+        # test that passing a custom takestep without attribute stepsize
+        takestep = myTakeStep2
+        i = 1
+        res = basinhopping(func2d_nograd, self.x0[i],
+                           minimizer_kwargs=self.kwargs_nograd,
+                           niter=self.niter, disp=self.disp,
+                           take_step=takestep)
+        assert_almost_equal(res.x, self.sol[i], self.tol)
+
+    def test_pass_accept_test(self):
+        # test passing a custom accept test
+        # makes sure it's being used and ensures all the possible return values
+        # are accepted.
+        accept_test = MyAcceptTest()
+        i = 1
+        # there's no point in running it more than a few steps.
+        basinhopping(func2d, self.x0[i], minimizer_kwargs=self.kwargs,
+                     niter=10, disp=self.disp, accept_test=accept_test)
+        assert_(accept_test.been_called)
+
+    def test_pass_callback(self):
+        # test passing a custom callback function
+        # This makes sure it's being used. It also returns True after 10 steps
+        # to ensure that it's stopping early.
+        callback = MyCallBack()
+        i = 1
+        # there's no point in running it more than a few steps.
+        res = basinhopping(func2d, self.x0[i], minimizer_kwargs=self.kwargs,
+                           niter=30, disp=self.disp, callback=callback)
+        assert_(callback.been_called)
+        assert_("callback" in res.message[0])
+        # One of the calls of MyCallBack is during BasinHoppingRunner
+        # construction, so there are only 9 remaining before MyCallBack stops
+        # the minimization.
+        assert_equal(res.nit, 9)
+
+    def test_minimizer_fail(self):
+        # test if a minimizer fails
+        i = 1
+        self.kwargs["options"] = dict(maxiter=0)
+        self.niter = 10
+        res = basinhopping(func2d, self.x0[i], minimizer_kwargs=self.kwargs,
+                           niter=self.niter, disp=self.disp)
+        # the number of failed minimizations should be the number of
+        # iterations + 1
+        assert_equal(res.nit + 1, res.minimization_failures)
+
+    def test_niter_zero(self):
+        # gh5915, what happens if you call basinhopping with niter=0
+        i = 0
+        basinhopping(func1d, self.x0[i], minimizer_kwargs=self.kwargs,
+                     niter=0, disp=self.disp)
+
+    def test_seed_reproducibility(self):
+        # seed should ensure reproducibility between runs
+        minimizer_kwargs = {"method": "L-BFGS-B", "jac": True}
+
+        f_1 = []
+
+        def callback(x, f, accepted):
+            f_1.append(f)
+
+        basinhopping(func2d, [1.0, 1.0], minimizer_kwargs=minimizer_kwargs,
+                     niter=10, callback=callback, seed=10)
+
+        f_2 = []
+
+        def callback2(x, f, accepted):
+            f_2.append(f)
+
+        basinhopping(func2d, [1.0, 1.0], minimizer_kwargs=minimizer_kwargs,
+                     niter=10, callback=callback2, seed=10)
+        assert_equal(np.array(f_1), np.array(f_2))
+
+    def test_random_gen(self):
+        # check that np.random.Generator can be used (numpy >= 1.17)
+        rng = np.random.default_rng(1)
+
+        minimizer_kwargs = {"method": "L-BFGS-B", "jac": True}
+
+        res1 = basinhopping(func2d, [1.0, 1.0],
+                            minimizer_kwargs=minimizer_kwargs,
+                            niter=10, seed=rng)
+
+        rng = np.random.default_rng(1)
+        res2 = basinhopping(func2d, [1.0, 1.0],
+                            minimizer_kwargs=minimizer_kwargs,
+                            niter=10, seed=rng)
+        assert_equal(res1.x, res2.x)
+
+    def test_monotonic_basin_hopping(self):
+        # test 1-D minimizations with gradient and T=0
+        i = 0
+        res = basinhopping(func1d, self.x0[i], minimizer_kwargs=self.kwargs,
+                           niter=self.niter, disp=self.disp, T=0)
+        assert_almost_equal(res.x, self.sol[i], self.tol)
+
+
+class Test_Storage:
+    def setup_method(self):
+        self.x0 = np.array(1)
+        self.f0 = 0
+
+        minres = OptimizeResult(success=True)
+        minres.x = self.x0
+        minres.fun = self.f0
+
+        self.storage = Storage(minres)
+
+    def test_higher_f_rejected(self):
+        new_minres = OptimizeResult(success=True)
+        new_minres.x = self.x0 + 1
+        new_minres.fun = self.f0 + 1
+
+        ret = self.storage.update(new_minres)
+        minres = self.storage.get_lowest()
+        assert_equal(self.x0, minres.x)
+        assert_equal(self.f0, minres.fun)
+        assert_(not ret)
+
+    @pytest.mark.parametrize('success', [True, False])
+    def test_lower_f_accepted(self, success):
+        new_minres = OptimizeResult(success=success)
+        new_minres.x = self.x0 + 1
+        new_minres.fun = self.f0 - 1
+
+        ret = self.storage.update(new_minres)
+        minres = self.storage.get_lowest()
+        assert (self.x0 != minres.x) == success  # can't use `is`
+        assert (self.f0 != minres.fun) == success  # left side is NumPy bool
+        assert ret is success
+
+
+class Test_RandomDisplacement:
+    def setup_method(self):
+        self.stepsize = 1.0
+        self.displace = RandomDisplacement(stepsize=self.stepsize)
+        self.N = 300000
+        self.x0 = np.zeros([self.N])
+
+    def test_random(self):
+        # the mean should be 0
+        # the variance should be (2*stepsize)**2 / 12
+        # note these tests are random, they will fail from time to time
+        x = self.displace(self.x0)
+        v = (2. * self.stepsize) ** 2 / 12
+        assert_almost_equal(np.mean(x), 0., 1)
+        assert_almost_equal(np.var(x), v, 1)
+
+
+class Test_Metropolis:
+    def setup_method(self):
+        self.T = 2.
+        self.met = Metropolis(self.T)
+        self.res_new = OptimizeResult(success=True, fun=0.)
+        self.res_old = OptimizeResult(success=True, fun=1.)
+
+    def test_boolean_return(self):
+        # the return must be a bool, else an error will be raised in
+        # basinhopping
+        ret = self.met(res_new=self.res_new, res_old=self.res_old)
+        assert isinstance(ret, bool)
+
+    def test_lower_f_accepted(self):
+        assert_(self.met(res_new=self.res_new, res_old=self.res_old))
+
+    def test_accept(self):
+        # test that steps are randomly accepted for f_new > f_old
+        one_accept = False
+        one_reject = False
+        for i in range(1000):
+            if one_accept and one_reject:
+                break
+            res_new = OptimizeResult(success=True, fun=1.)
+            res_old = OptimizeResult(success=True, fun=0.5)
+            ret = self.met(res_new=res_new, res_old=res_old)
+            if ret:
+                one_accept = True
+            else:
+                one_reject = True
+        assert_(one_accept)
+        assert_(one_reject)
+
+    def test_GH7495(self):
+        # an overflow in exp was producing a RuntimeWarning
+        # create own object here in case someone changes self.T
+        met = Metropolis(2)
+        res_new = OptimizeResult(success=True, fun=0.)
+        res_old = OptimizeResult(success=True, fun=2000)
+        with np.errstate(over='raise'):
+            met.accept_reject(res_new=res_new, res_old=res_old)
+
+    def test_gh7799(self):
+        # gh-7799 reported a problem in which local search was successful but
+        # basinhopping returned an invalid solution. Show that this is fixed.
+        def func(x):
+            return (x**2-8)**2+(x+2)**2
+
+        x0 = -4
+        limit = 50  # Constrain to func value >= 50
+        con = {'type': 'ineq', 'fun': lambda x: func(x) - limit},
+        res = basinhopping(func, x0, 30, minimizer_kwargs={'constraints': con})
+        assert res.success
+        assert_allclose(res.fun, limit, rtol=1e-6)
+
+    def test_accept_gh7799(self):
+        # Metropolis should not accept the result of an unsuccessful new local
+        # search if the old local search was successful
+
+        met = Metropolis(0)  # monotonic basin hopping
+        res_new = OptimizeResult(success=True, fun=0.)
+        res_old = OptimizeResult(success=True, fun=1.)
+
+        # if new local search was successful and energy is lower, accept
+        assert met(res_new=res_new, res_old=res_old)
+        # if new res is unsuccessful, don't accept - even if energy is lower
+        res_new.success = False
+        assert not met(res_new=res_new, res_old=res_old)
+        # ...unless the old res was unsuccessful, too. In that case, why not?
+        res_old.success = False
+        assert met(res_new=res_new, res_old=res_old)
+
+    def test_reject_all_gh7799(self):
+        # Test the behavior when there is no feasible solution
+        def fun(x):
+            return x@x
+
+        def constraint(x):
+            return x + 1
+
+        kwargs = {'constraints': {'type': 'eq', 'fun': constraint},
+                  'bounds': [(0, 1), (0, 1)], 'method': 'slsqp'}
+        res = basinhopping(fun, x0=[2, 3], niter=10, minimizer_kwargs=kwargs)
+        assert not res.success
+
+
+class Test_AdaptiveStepsize:
+    def setup_method(self):
+        self.stepsize = 1.
+        self.ts = RandomDisplacement(stepsize=self.stepsize)
+        self.target_accept_rate = 0.5
+        self.takestep = AdaptiveStepsize(takestep=self.ts, verbose=False,
+                                         accept_rate=self.target_accept_rate)
+
+    def test_adaptive_increase(self):
+        # if few steps are rejected, the stepsize should increase
+        x = 0.
+        self.takestep(x)
+        self.takestep.report(False)
+        for i in range(self.takestep.interval):
+            self.takestep(x)
+            self.takestep.report(True)
+        assert_(self.ts.stepsize > self.stepsize)
+
+    def test_adaptive_decrease(self):
+        # if few steps are rejected, the stepsize should increase
+        x = 0.
+        self.takestep(x)
+        self.takestep.report(True)
+        for i in range(self.takestep.interval):
+            self.takestep(x)
+            self.takestep.report(False)
+        assert_(self.ts.stepsize < self.stepsize)
+
+    def test_all_accepted(self):
+        # test that everything works OK if all steps were accepted
+        x = 0.
+        for i in range(self.takestep.interval + 1):
+            self.takestep(x)
+            self.takestep.report(True)
+        assert_(self.ts.stepsize > self.stepsize)
+
+    def test_all_rejected(self):
+        # test that everything works OK if all steps were rejected
+        x = 0.
+        for i in range(self.takestep.interval + 1):
+            self.takestep(x)
+            self.takestep.report(False)
+        assert_(self.ts.stepsize < self.stepsize)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__differential_evolution.py

@@ -0,0 +1,1677 @@
+"""
+Unit tests for the differential global minimization algorithm.
+"""
+import multiprocessing
+import platform
+
+from scipy.optimize._differentialevolution import (DifferentialEvolutionSolver,
+                                                   _ConstraintWrapper)
+from scipy.optimize import differential_evolution, OptimizeResult
+from scipy.optimize._constraints import (Bounds, NonlinearConstraint,
+                                         LinearConstraint)
+from scipy.optimize import rosen, minimize
+from scipy.sparse import csr_matrix
+from scipy import stats
+
+import numpy as np
+from numpy.testing import (assert_equal, assert_allclose, assert_almost_equal,
+                           assert_string_equal, assert_, suppress_warnings)
+from pytest import raises as assert_raises, warns
+import pytest
+
+
+class TestDifferentialEvolutionSolver:
+
+    def setup_method(self):
+        self.old_seterr = np.seterr(invalid='raise')
+        self.limits = np.array([[0., 0.],
+                                [2., 2.]])
+        self.bounds = [(0., 2.), (0., 2.)]
+
+        self.dummy_solver = DifferentialEvolutionSolver(self.quadratic,
+                                                        [(0, 100)])
+
+        # dummy_solver2 will be used to test mutation strategies
+        self.dummy_solver2 = DifferentialEvolutionSolver(self.quadratic,
+                                                         [(0, 1)],
+                                                         popsize=7,
+                                                         mutation=0.5)
+        # create a population that's only 7 members long
+        # [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7]
+        population = np.atleast_2d(np.arange(0.1, 0.8, 0.1)).T
+        self.dummy_solver2.population = population
+
+    def teardown_method(self):
+        np.seterr(**self.old_seterr)
+
+    def quadratic(self, x):
+        return x[0]**2
+
+    def test__strategy_resolves(self):
+        # test that the correct mutation function is resolved by
+        # different requested strategy arguments
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='best1exp')
+        assert_equal(solver.strategy, 'best1exp')
+        assert_equal(solver.mutation_func.__name__, '_best1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='best1bin')
+        assert_equal(solver.strategy, 'best1bin')
+        assert_equal(solver.mutation_func.__name__, '_best1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='rand1bin')
+        assert_equal(solver.strategy, 'rand1bin')
+        assert_equal(solver.mutation_func.__name__, '_rand1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='rand1exp')
+        assert_equal(solver.strategy, 'rand1exp')
+        assert_equal(solver.mutation_func.__name__, '_rand1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='rand2exp')
+        assert_equal(solver.strategy, 'rand2exp')
+        assert_equal(solver.mutation_func.__name__, '_rand2')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='best2bin')
+        assert_equal(solver.strategy, 'best2bin')
+        assert_equal(solver.mutation_func.__name__, '_best2')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='rand2bin')
+        assert_equal(solver.strategy, 'rand2bin')
+        assert_equal(solver.mutation_func.__name__, '_rand2')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='rand2exp')
+        assert_equal(solver.strategy, 'rand2exp')
+        assert_equal(solver.mutation_func.__name__, '_rand2')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='randtobest1bin')
+        assert_equal(solver.strategy, 'randtobest1bin')
+        assert_equal(solver.mutation_func.__name__, '_randtobest1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='randtobest1exp')
+        assert_equal(solver.strategy, 'randtobest1exp')
+        assert_equal(solver.mutation_func.__name__, '_randtobest1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='currenttobest1bin')
+        assert_equal(solver.strategy, 'currenttobest1bin')
+        assert_equal(solver.mutation_func.__name__, '_currenttobest1')
+
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='currenttobest1exp')
+        assert_equal(solver.strategy, 'currenttobest1exp')
+        assert_equal(solver.mutation_func.__name__, '_currenttobest1')
+
+    def test__mutate1(self):
+        # strategies */1/*, i.e. rand/1/bin, best/1/exp, etc.
+        result = np.array([0.05])
+        trial = self.dummy_solver2._best1((2, 3, 4, 5, 6))
+        assert_allclose(trial, result)
+
+        result = np.array([0.25])
+        trial = self.dummy_solver2._rand1((2, 3, 4, 5, 6))
+        assert_allclose(trial, result)
+
+    def test__mutate2(self):
+        # strategies */2/*, i.e. rand/2/bin, best/2/exp, etc.
+        # [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7]
+
+        result = np.array([-0.1])
+        trial = self.dummy_solver2._best2((2, 3, 4, 5, 6))
+        assert_allclose(trial, result)
+
+        result = np.array([0.1])
+        trial = self.dummy_solver2._rand2((2, 3, 4, 5, 6))
+        assert_allclose(trial, result)
+
+    def test__randtobest1(self):
+        # strategies randtobest/1/*
+        result = np.array([0.15])
+        trial = self.dummy_solver2._randtobest1((2, 3, 4, 5, 6))
+        assert_allclose(trial, result)
+
+    def test__currenttobest1(self):
+        # strategies currenttobest/1/*
+        result = np.array([0.1])
+        trial = self.dummy_solver2._currenttobest1(1, (2, 3, 4, 5, 6))
+        assert_allclose(trial, result)
+
+    def test_can_init_with_dithering(self):
+        mutation = (0.5, 1)
+        solver = DifferentialEvolutionSolver(self.quadratic,
+                                             self.bounds,
+                                             mutation=mutation)
+
+        assert_equal(solver.dither, list(mutation))
+
+    def test_invalid_mutation_values_arent_accepted(self):
+        func = rosen
+        mutation = (0.5, 3)
+        assert_raises(ValueError,
+                          DifferentialEvolutionSolver,
+                          func,
+                          self.bounds,
+                          mutation=mutation)
+
+        mutation = (-1, 1)
+        assert_raises(ValueError,
+                          DifferentialEvolutionSolver,
+                          func,
+                          self.bounds,
+                          mutation=mutation)
+
+        mutation = (0.1, np.nan)
+        assert_raises(ValueError,
+                          DifferentialEvolutionSolver,
+                          func,
+                          self.bounds,
+                          mutation=mutation)
+
+        mutation = 0.5
+        solver = DifferentialEvolutionSolver(func,
+                                             self.bounds,
+                                             mutation=mutation)
+        assert_equal(0.5, solver.scale)
+        assert_equal(None, solver.dither)
+
+    def test_invalid_functional(self):
+        def func(x):
+            return np.array([np.sum(x ** 2), np.sum(x)])
+
+        with assert_raises(
+                RuntimeError,
+                match=r"func\(x, \*args\) must return a scalar value"):
+            differential_evolution(func, [(-2, 2), (-2, 2)])
+
+    def test__scale_parameters(self):
+        trial = np.array([0.3])
+        assert_equal(30, self.dummy_solver._scale_parameters(trial))
+
+        # it should also work with the limits reversed
+        self.dummy_solver.limits = np.array([[100], [0.]])
+        assert_equal(30, self.dummy_solver._scale_parameters(trial))
+
+    def test__unscale_parameters(self):
+        trial = np.array([30])
+        assert_equal(0.3, self.dummy_solver._unscale_parameters(trial))
+
+        # it should also work with the limits reversed
+        self.dummy_solver.limits = np.array([[100], [0.]])
+        assert_equal(0.3, self.dummy_solver._unscale_parameters(trial))
+
+    def test_equal_bounds(self):
+        with np.errstate(invalid='raise'):
+            solver = DifferentialEvolutionSolver(
+                self.quadratic,
+                bounds=[(2.0, 2.0), (1.0, 3.0)]
+            )
+            v = solver._unscale_parameters([2.0, 2.0])
+            assert_allclose(v, 0.5)
+
+        res = differential_evolution(self.quadratic, [(2.0, 2.0), (3.0, 3.0)])
+        assert_equal(res.x, [2.0, 3.0])
+
+    def test__ensure_constraint(self):
+        trial = np.array([1.1, -100, 0.9, 2., 300., -0.00001])
+        self.dummy_solver._ensure_constraint(trial)
+
+        assert_equal(trial[2], 0.9)
+        assert_(np.logical_and(trial >= 0, trial <= 1).all())
+
+    def test_differential_evolution(self):
+        # test that the Jmin of DifferentialEvolutionSolver
+        # is the same as the function evaluation
+        solver = DifferentialEvolutionSolver(
+            self.quadratic, [(-2, 2)], maxiter=1, polish=False
+        )
+        result = solver.solve()
+        assert_equal(result.fun, self.quadratic(result.x))
+
+        solver = DifferentialEvolutionSolver(
+            self.quadratic, [(-2, 2)], maxiter=1, polish=True
+        )
+        result = solver.solve()
+        assert_equal(result.fun, self.quadratic(result.x))
+
+    def test_best_solution_retrieval(self):
+        # test that the getter property method for the best solution works.
+        solver = DifferentialEvolutionSolver(self.quadratic, [(-2, 2)])
+        result = solver.solve()
+        assert_equal(result.x, solver.x)
+
+    def test_intermediate_result(self):
+        # Check that intermediate result object passed into the callback
+        # function contains the expected information and that raising
+        # `StopIteration` causes the expected behavior.
+        maxiter = 10
+
+        def func(x):
+            val = rosen(x)
+            if val < func.val:
+                func.x = x
+                func.val = val
+            return val
+        func.x = None
+        func.val = np.inf
+
+        def callback(intermediate_result):
+            callback.nit += 1
+            callback.intermediate_result = intermediate_result
+            assert intermediate_result.population.ndim == 2
+            assert intermediate_result.population.shape[1] == 2
+            assert intermediate_result.nit == callback.nit
+
+            # Check that `x` and `fun` attributes are the best found so far
+            assert_equal(intermediate_result.x, callback.func.x)
+            assert_equal(intermediate_result.fun, callback.func.val)
+
+            # Check for consistency between `fun`, `population_energies`,
+            # `x`, and `population`
+            assert_equal(intermediate_result.fun, rosen(intermediate_result.x))
+            for i in range(len(intermediate_result.population_energies)):
+                res = intermediate_result.population_energies[i]
+                ref = rosen(intermediate_result.population[i])
+                assert_equal(res, ref)
+            assert_equal(intermediate_result.x,
+                         intermediate_result.population[0])
+            assert_equal(intermediate_result.fun,
+                         intermediate_result.population_energies[0])
+
+            assert intermediate_result.message == 'in progress'
+            assert intermediate_result.success is True
+            assert isinstance(intermediate_result, OptimizeResult)
+            if callback.nit == maxiter:
+                raise StopIteration
+        callback.nit = 0
+        callback.intermediate_result = None
+        callback.func = func
+
+        bounds = [(0, 2), (0, 2)]
+        kwargs = dict(func=func, bounds=bounds, seed=838245, polish=False)
+        res = differential_evolution(**kwargs, callback=callback)
+        ref = differential_evolution(**kwargs, maxiter=maxiter)
+
+        # Check that final `intermediate_result` is equivalent to returned
+        # result object and that terminating with callback `StopIteration`
+        # after `maxiter` iterations is equivalent to terminating with
+        # `maxiter` parameter.
+        assert res.success is ref.success is False
+        assert callback.nit == res.nit == maxiter
+        assert res.message == 'callback function requested stop early'
+        assert ref.message == 'Maximum number of iterations has been exceeded.'
+        for field, val in ref.items():
+            if field in {'message', 'success'}:  # checked separately
+                continue
+            assert_equal(callback.intermediate_result[field], val)
+            assert_equal(res[field], val)
+
+        # Check that polish occurs after `StopIteration` as advertised
+        callback.nit = 0
+        func.val = np.inf
+        kwargs['polish'] = True
+        res = differential_evolution(**kwargs, callback=callback)
+        assert res.fun < ref.fun
+
+    def test_callback_terminates(self):
+        # test that if the callback returns true, then the minimization halts
+        bounds = [(0, 2), (0, 2)]
+        expected_msg = 'callback function requested stop early'
+        def callback_python_true(param, convergence=0.):
+            return True
+
+        result = differential_evolution(
+            rosen, bounds, callback=callback_python_true
+        )
+        assert_string_equal(result.message, expected_msg)
+
+        # if callback raises StopIteration then solve should be interrupted
+        def callback_stop(intermediate_result):
+            raise StopIteration
+
+        result = differential_evolution(rosen, bounds, callback=callback_stop)
+        assert not result.success
+
+        def callback_evaluates_true(param, convergence=0.):
+            # DE should stop if bool(self.callback) is True
+            return [10]
+
+        result = differential_evolution(rosen, bounds, callback=callback_evaluates_true)
+        assert_string_equal(result.message, expected_msg)
+        assert not result.success
+
+        def callback_evaluates_false(param, convergence=0.):
+            return []
+
+        result = differential_evolution(rosen, bounds,
+                                        callback=callback_evaluates_false)
+        assert result.success
+
+    def test_args_tuple_is_passed(self):
+        # test that the args tuple is passed to the cost function properly.
+        bounds = [(-10, 10)]
+        args = (1., 2., 3.)
+
+        def quadratic(x, *args):
+            if type(args) != tuple:
+                raise ValueError('args should be a tuple')
+            return args[0] + args[1] * x + args[2] * x**2.
+
+        result = differential_evolution(quadratic,
+                                        bounds,
+                                        args=args,
+                                        polish=True)
+        assert_almost_equal(result.fun, 2 / 3.)
+
+    def test_init_with_invalid_strategy(self):
+        # test that passing an invalid strategy raises ValueError
+        func = rosen
+        bounds = [(-3, 3)]
+        assert_raises(ValueError,
+                          differential_evolution,
+                          func,
+                          bounds,
+                          strategy='abc')
+
+    def test_bounds_checking(self):
+        # test that the bounds checking works
+        func = rosen
+        bounds = [(-3)]
+        assert_raises(ValueError,
+                          differential_evolution,
+                          func,
+                          bounds)
+        bounds = [(-3, 3), (3, 4, 5)]
+        assert_raises(ValueError,
+                          differential_evolution,
+                          func,
+                          bounds)
+
+        # test that we can use a new-type Bounds object
+        result = differential_evolution(rosen, Bounds([0, 0], [2, 2]))
+        assert_almost_equal(result.x, (1., 1.))
+
+    def test_select_samples(self):
+        # select_samples should return 5 separate random numbers.
+        limits = np.arange(12., dtype='float64').reshape(2, 6)
+        bounds = list(zip(limits[0, :], limits[1, :]))
+        solver = DifferentialEvolutionSolver(None, bounds, popsize=1)
+        candidate = 0
+        r1, r2, r3, r4, r5 = solver._select_samples(candidate, 5)
+        assert_equal(
+            len(np.unique(np.array([candidate, r1, r2, r3, r4, r5]))), 6)
+
+    def test_maxiter_stops_solve(self):
+        # test that if the maximum number of iterations is exceeded
+        # the solver stops.
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, maxiter=1)
+        result = solver.solve()
+        assert_equal(result.success, False)
+        assert_equal(result.message,
+                        'Maximum number of iterations has been exceeded.')
+
+    def test_maxfun_stops_solve(self):
+        # test that if the maximum number of function evaluations is exceeded
+        # during initialisation the solver stops
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, maxfun=1,
+                                             polish=False)
+        result = solver.solve()
+
+        assert_equal(result.nfev, 2)
+        assert_equal(result.success, False)
+        assert_equal(result.message,
+                     'Maximum number of function evaluations has '
+                     'been exceeded.')
+
+        # test that if the maximum number of function evaluations is exceeded
+        # during the actual minimisation, then the solver stops.
+        # Have to turn polishing off, as this will still occur even if maxfun
+        # is reached. For popsize=5 and len(bounds)=2, then there are only 10
+        # function evaluations during initialisation.
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             popsize=5,
+                                             polish=False,
+                                             maxfun=40)
+        result = solver.solve()
+
+        assert_equal(result.nfev, 41)
+        assert_equal(result.success, False)
+        assert_equal(result.message,
+                     'Maximum number of function evaluations has '
+                     'been exceeded.')
+
+        # now repeat for updating='deferred version
+        # 47 function evaluations is not a multiple of the population size,
+        # so maxfun is reached partway through a population evaluation.
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             popsize=5,
+                                             polish=False,
+                                             maxfun=47,
+                                             updating='deferred')
+        result = solver.solve()
+
+        assert_equal(result.nfev, 47)
+        assert_equal(result.success, False)
+        assert_equal(result.message,
+                     'Maximum number of function evaluations has '
+                     'been reached.')
+
+    def test_quadratic(self):
+        # test the quadratic function from object
+        solver = DifferentialEvolutionSolver(self.quadratic,
+                                             [(-100, 100)],
+                                             tol=0.02)
+        solver.solve()
+        assert_equal(np.argmin(solver.population_energies), 0)
+
+    def test_quadratic_from_diff_ev(self):
+        # test the quadratic function from differential_evolution function
+        differential_evolution(self.quadratic,
+                               [(-100, 100)],
+                               tol=0.02)
+
+    def test_seed_gives_repeatability(self):
+        result = differential_evolution(self.quadratic,
+                                        [(-100, 100)],
+                                        polish=False,
+                                        seed=1,
+                                        tol=0.5)
+        result2 = differential_evolution(self.quadratic,
+                                        [(-100, 100)],
+                                        polish=False,
+                                        seed=1,
+                                        tol=0.5)
+        assert_equal(result.x, result2.x)
+        assert_equal(result.nfev, result2.nfev)
+
+    def test_random_generator(self):
+        # check that np.random.Generator can be used (numpy >= 1.17)
+        # obtain a np.random.Generator object
+        rng = np.random.default_rng()
+
+        inits = ['random', 'latinhypercube', 'sobol', 'halton']
+        for init in inits:
+            differential_evolution(self.quadratic,
+                                   [(-100, 100)],
+                                   polish=False,
+                                   seed=rng,
+                                   tol=0.5,
+                                   init=init)
+
+    def test_exp_runs(self):
+        # test whether exponential mutation loop runs
+        solver = DifferentialEvolutionSolver(rosen,
+                                             self.bounds,
+                                             strategy='best1exp',
+                                             maxiter=1)
+
+        solver.solve()
+
+    def test_gh_4511_regression(self):
+        # This modification of the differential evolution docstring example
+        # uses a custom popsize that had triggered an off-by-one error.
+        # Because we do not care about solving the optimization problem in
+        # this test, we use maxiter=1 to reduce the testing time.
+        bounds = [(-5, 5), (-5, 5)]
+        # result = differential_evolution(rosen, bounds, popsize=1815,
+        #                                 maxiter=1)
+
+        # the original issue arose because of rounding error in arange, with
+        # linspace being a much better solution. 1815 is quite a large popsize
+        # to use and results in a long test time (~13s). I used the original
+        # issue to figure out the lowest number of samples that would cause
+        # this rounding error to occur, 49.
+        differential_evolution(rosen, bounds, popsize=49, maxiter=1)
+
+    def test_calculate_population_energies(self):
+        # if popsize is 3, then the overall generation has size (6,)
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, popsize=3)
+        solver._calculate_population_energies(solver.population)
+        solver._promote_lowest_energy()
+        assert_equal(np.argmin(solver.population_energies), 0)
+
+        # initial calculation of the energies should require 6 nfev.
+        assert_equal(solver._nfev, 6)
+
+    def test_iteration(self):
+        # test that DifferentialEvolutionSolver is iterable
+        # if popsize is 3, then the overall generation has size (6,)
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, popsize=3,
+                                             maxfun=12)
+        x, fun = next(solver)
+        assert_equal(np.size(x, 0), 2)
+
+        # 6 nfev are required for initial calculation of energies, 6 nfev are
+        # required for the evolution of the 6 population members.
+        assert_equal(solver._nfev, 12)
+
+        # the next generation should halt because it exceeds maxfun
+        assert_raises(StopIteration, next, solver)
+
+        # check a proper minimisation can be done by an iterable solver
+        solver = DifferentialEvolutionSolver(rosen, self.bounds)
+        _, fun_prev = next(solver)
+        for i, soln in enumerate(solver):
+            x_current, fun_current = soln
+            assert fun_prev >= fun_current
+            _, fun_prev = x_current, fun_current
+            # need to have this otherwise the solver would never stop.
+            if i == 50:
+                break
+
+    def test_convergence(self):
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, tol=0.2,
+                                             polish=False)
+        solver.solve()
+        assert_(solver.convergence < 0.2)
+
+    def test_maxiter_none_GH5731(self):
+        # Pre 0.17 the previous default for maxiter and maxfun was None.
+        # the numerical defaults are now 1000 and np.inf. However, some scripts
+        # will still supply None for both of those, this will raise a TypeError
+        # in the solve method.
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, maxiter=None,
+                                             maxfun=None)
+        solver.solve()
+
+    def test_population_initiation(self):
+        # test the different modes of population initiation
+
+        # init must be either 'latinhypercube' or 'random'
+        # raising ValueError is something else is passed in
+        assert_raises(ValueError,
+                      DifferentialEvolutionSolver,
+                      *(rosen, self.bounds),
+                      **{'init': 'rubbish'})
+
+        solver = DifferentialEvolutionSolver(rosen, self.bounds)
+
+        # check that population initiation:
+        # 1) resets _nfev to 0
+        # 2) all population energies are np.inf
+        solver.init_population_random()
+        assert_equal(solver._nfev, 0)
+        assert_(np.all(np.isinf(solver.population_energies)))
+
+        solver.init_population_lhs()
+        assert_equal(solver._nfev, 0)
+        assert_(np.all(np.isinf(solver.population_energies)))
+
+        solver.init_population_qmc(qmc_engine='halton')
+        assert_equal(solver._nfev, 0)
+        assert_(np.all(np.isinf(solver.population_energies)))
+
+        solver = DifferentialEvolutionSolver(rosen, self.bounds, init='sobol')
+        solver.init_population_qmc(qmc_engine='sobol')
+        assert_equal(solver._nfev, 0)
+        assert_(np.all(np.isinf(solver.population_energies)))
+
+        # we should be able to initialize with our own array
+        population = np.linspace(-1, 3, 10).reshape(5, 2)
+        solver = DifferentialEvolutionSolver(rosen, self.bounds,
+                                             init=population,
+                                             strategy='best2bin',
+                                             atol=0.01, seed=1, popsize=5)
+
+        assert_equal(solver._nfev, 0)
+        assert_(np.all(np.isinf(solver.population_energies)))
+        assert_(solver.num_population_members == 5)
+        assert_(solver.population_shape == (5, 2))
+
+        # check that the population was initialized correctly
+        unscaled_population = np.clip(solver._unscale_parameters(population),
+                                      0, 1)
+        assert_almost_equal(solver.population[:5], unscaled_population)
+
+        # population values need to be clipped to bounds
+        assert_almost_equal(np.min(solver.population[:5]), 0)
+        assert_almost_equal(np.max(solver.population[:5]), 1)
+
+        # shouldn't be able to initialize with an array if it's the wrong shape
+        # this would have too many parameters
+        population = np.linspace(-1, 3, 15).reshape(5, 3)
+        assert_raises(ValueError,
+                      DifferentialEvolutionSolver,
+                      *(rosen, self.bounds),
+                      **{'init': population})
+
+        # provide an initial solution
+        # bounds are [(0, 2), (0, 2)]
+        x0 = np.random.uniform(low=0.0, high=2.0, size=2)
+        solver = DifferentialEvolutionSolver(
+            rosen, self.bounds, x0=x0
+        )
+        # parameters are scaled to unit interval
+        assert_allclose(solver.population[0], x0 / 2.0)
+
+    def test_x0(self):
+        # smoke test that checks that x0 is usable.
+        res = differential_evolution(rosen, self.bounds, x0=[0.2, 0.8])
+        assert res.success
+
+        # check what happens if some of the x0 lay outside the bounds
+        with assert_raises(ValueError):
+            differential_evolution(rosen, self.bounds, x0=[0.2, 2.1])
+
+    def test_infinite_objective_function(self):
+        # Test that there are no problems if the objective function
+        # returns inf on some runs
+        def sometimes_inf(x):
+            if x[0] < .5:
+                return np.inf
+            return x[1]
+        bounds = [(0, 1), (0, 1)]
+        differential_evolution(sometimes_inf, bounds=bounds, disp=False)
+
+    def test_deferred_updating(self):
+        # check setting of deferred updating, with default workers
+        bounds = [(0., 2.), (0., 2.)]
+        solver = DifferentialEvolutionSolver(rosen, bounds, updating='deferred')
+        assert_(solver._updating == 'deferred')
+        assert_(solver._mapwrapper._mapfunc is map)
+        solver.solve()
+
+    def test_immediate_updating(self):
+        # check setting of immediate updating, with default workers
+        bounds = [(0., 2.), (0., 2.)]
+        solver = DifferentialEvolutionSolver(rosen, bounds)
+        assert_(solver._updating == 'immediate')
+
+        # Safely forking from a multithreaded process is
+        # problematic, and deprecated in Python 3.12, so
+        # we use a slower but portable alternative
+        # see gh-19848
+        ctx = multiprocessing.get_context("spawn")
+        with ctx.Pool(2) as p:
+            # should raise a UserWarning because the updating='immediate'
+            # is being overridden by the workers keyword
+            with warns(UserWarning):
+                with DifferentialEvolutionSolver(rosen, bounds, workers=p.map) as s:
+                    pass
+            assert s._updating == 'deferred'
+
+    def test_parallel(self):
+        # smoke test for parallelization with deferred updating
+        bounds = [(0., 2.), (0., 2.)]
+        with multiprocessing.Pool(2) as p, DifferentialEvolutionSolver(
+                rosen, bounds, updating='deferred', workers=p.map) as solver:
+            assert_(solver._mapwrapper.pool is not None)
+            assert_(solver._updating == 'deferred')
+            solver.solve()
+
+        with DifferentialEvolutionSolver(rosen, bounds, updating='deferred',
+                                         workers=2) as solver:
+            assert_(solver._mapwrapper.pool is not None)
+            assert_(solver._updating == 'deferred')
+            solver.solve()
+
+    def test_converged(self):
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)])
+        solver.solve()
+        assert_(solver.converged())
+
+    def test_constraint_violation_fn(self):
+        def constr_f(x):
+            return [x[0] + x[1]]
+
+        def constr_f2(x):
+            return np.array([x[0]**2 + x[1], x[0] - x[1]])
+
+        nlc = NonlinearConstraint(constr_f, -np.inf, 1.9)
+
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc))
+
+        cv = solver._constraint_violation_fn(np.array([1.0, 1.0]))
+        assert_almost_equal(cv, 0.1)
+
+        nlc2 = NonlinearConstraint(constr_f2, -np.inf, 1.8)
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc, nlc2))
+
+        # for multiple constraints the constraint violations should
+        # be concatenated.
+        xs = [(1.2, 1), (2.0, 2.0), (0.5, 0.5)]
+        vs = [(0.3, 0.64, 0.0), (2.1, 4.2, 0.0), (0, 0, 0)]
+
+        for x, v in zip(xs, vs):
+            cv = solver._constraint_violation_fn(np.array(x))
+            assert_allclose(cv, np.atleast_2d(v))
+
+        # vectorized calculation of a series of solutions
+        assert_allclose(
+            solver._constraint_violation_fn(np.array(xs)), np.array(vs)
+        )
+
+        # the following line is used in _calculate_population_feasibilities.
+        # _constraint_violation_fn returns an (1, M) array when
+        # x.shape == (N,), i.e. a single solution. Therefore this list
+        # comprehension should generate (S, 1, M) array.
+        constraint_violation = np.array([solver._constraint_violation_fn(x)
+                                         for x in np.array(xs)])
+        assert constraint_violation.shape == (3, 1, 3)
+
+        # we need reasonable error messages if the constraint function doesn't
+        # return the right thing
+        def constr_f3(x):
+            # returns (S, M), rather than (M, S)
+            return constr_f2(x).T
+
+        nlc2 = NonlinearConstraint(constr_f3, -np.inf, 1.8)
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc, nlc2),
+                                             vectorized=False)
+        solver.vectorized = True
+        with pytest.raises(
+                RuntimeError, match="An array returned from a Constraint"
+        ):
+            solver._constraint_violation_fn(np.array(xs))
+
+    def test_constraint_population_feasibilities(self):
+        def constr_f(x):
+            return [x[0] + x[1]]
+
+        def constr_f2(x):
+            return [x[0]**2 + x[1], x[0] - x[1]]
+
+        nlc = NonlinearConstraint(constr_f, -np.inf, 1.9)
+
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc))
+
+        # are population feasibilities correct
+        # [0.5, 0.5] corresponds to scaled values of [1., 1.]
+        feas, cv = solver._calculate_population_feasibilities(
+            np.array([[0.5, 0.5], [1., 1.]]))
+        assert_equal(feas, [False, False])
+        assert_almost_equal(cv, np.array([[0.1], [2.1]]))
+        assert cv.shape == (2, 1)
+
+        nlc2 = NonlinearConstraint(constr_f2, -np.inf, 1.8)
+
+        for vectorize in [False, True]:
+            solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                                 constraints=(nlc, nlc2),
+                                                 vectorized=vectorize,
+                                                 updating='deferred')
+
+            feas, cv = solver._calculate_population_feasibilities(
+                np.array([[0.5, 0.5], [0.6, 0.5]]))
+            assert_equal(feas, [False, False])
+            assert_almost_equal(cv, np.array([[0.1, 0.2, 0], [0.3, 0.64, 0]]))
+
+            feas, cv = solver._calculate_population_feasibilities(
+                np.array([[0.5, 0.5], [1., 1.]]))
+            assert_equal(feas, [False, False])
+            assert_almost_equal(cv, np.array([[0.1, 0.2, 0], [2.1, 4.2, 0]]))
+            assert cv.shape == (2, 3)
+
+            feas, cv = solver._calculate_population_feasibilities(
+                np.array([[0.25, 0.25], [1., 1.]]))
+            assert_equal(feas, [True, False])
+            assert_almost_equal(cv, np.array([[0.0, 0.0, 0.], [2.1, 4.2, 0]]))
+            assert cv.shape == (2, 3)
+
+    def test_constraint_solve(self):
+        def constr_f(x):
+            return np.array([x[0] + x[1]])
+
+        nlc = NonlinearConstraint(constr_f, -np.inf, 1.9)
+
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc))
+
+        # trust-constr warns if the constraint function is linear
+        with warns(UserWarning):
+            res = solver.solve()
+
+        assert constr_f(res.x) <= 1.9
+        assert res.success
+
+    def test_impossible_constraint(self):
+        def constr_f(x):
+            return np.array([x[0] + x[1]])
+
+        nlc = NonlinearConstraint(constr_f, -np.inf, -1)
+
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc), popsize=3,
+                                             seed=1)
+
+        # a UserWarning is issued because the 'trust-constr' polishing is
+        # attempted on the least infeasible solution found.
+        with warns(UserWarning):
+            res = solver.solve()
+
+        assert res.maxcv > 0
+        assert not res.success
+
+        # test _promote_lowest_energy works when none of the population is
+        # feasible. In this case, the solution with the lowest constraint
+        # violation should be promoted.
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc), polish=False)
+        next(solver)
+        assert not solver.feasible.all()
+        assert not np.isfinite(solver.population_energies).all()
+
+        # now swap two of the entries in the population
+        l = 20
+        cv = solver.constraint_violation[0]
+
+        solver.population_energies[[0, l]] = solver.population_energies[[l, 0]]
+        solver.population[[0, l], :] = solver.population[[l, 0], :]
+        solver.constraint_violation[[0, l], :] = (
+            solver.constraint_violation[[l, 0], :])
+
+        solver._promote_lowest_energy()
+        assert_equal(solver.constraint_violation[0], cv)
+
+    def test_accept_trial(self):
+        # _accept_trial(self, energy_trial, feasible_trial, cv_trial,
+        #               energy_orig, feasible_orig, cv_orig)
+        def constr_f(x):
+            return [x[0] + x[1]]
+        nlc = NonlinearConstraint(constr_f, -np.inf, 1.9)
+        solver = DifferentialEvolutionSolver(rosen, [(0, 2), (0, 2)],
+                                             constraints=(nlc))
+        fn = solver._accept_trial
+        # both solutions are feasible, select lower energy
+        assert fn(0.1, True, np.array([0.]), 1.0, True, np.array([0.]))
+        assert (fn(1.0, True, np.array([0.0]), 0.1, True, np.array([0.0])) is False)
+        assert fn(0.1, True, np.array([0.]), 0.1, True, np.array([0.]))
+
+        # trial is feasible, original is not
+        assert fn(9.9, True, np.array([0.]), 1.0, False, np.array([1.]))
+
+        # trial and original are infeasible
+        # cv_trial have to be <= cv_original to be better
+        assert (fn(0.1, False, np.array([0.5, 0.5]),
+                   1.0, False, np.array([1., 1.0])))
+        assert (fn(0.1, False, np.array([0.5, 0.5]),
+                   1.0, False, np.array([1., 0.50])))
+        assert not (fn(1.0, False, np.array([0.5, 0.5]),
+                       1.0, False, np.array([1.0, 0.4])))
+
+    def test_constraint_wrapper(self):
+        lb = np.array([0, 20, 30])
+        ub = np.array([0.5, np.inf, 70])
+        x0 = np.array([1, 2, 3])
+        pc = _ConstraintWrapper(Bounds(lb, ub), x0)
+        assert (pc.violation(x0) > 0).any()
+        assert (pc.violation([0.25, 21, 31]) == 0).all()
+
+        # check vectorized Bounds constraint
+        xs = np.arange(1, 16).reshape(5, 3)
+        violations = []
+        for x in xs:
+            violations.append(pc.violation(x))
+        np.testing.assert_allclose(pc.violation(xs.T), np.array(violations).T)
+
+        x0 = np.array([1, 2, 3, 4])
+        A = np.array([[1, 2, 3, 4], [5, 0, 0, 6], [7, 0, 8, 0]])
+        pc = _ConstraintWrapper(LinearConstraint(A, -np.inf, 0), x0)
+        assert (pc.violation(x0) > 0).any()
+        assert (pc.violation([-10, 2, -10, 4]) == 0).all()
+
+        # check vectorized LinearConstraint, for 7 lots of parameter vectors
+        # with each parameter vector being 4 long, with 3 constraints
+        # xs is the same shape as stored in the differential evolution
+        # population, but it's sent to the violation function as (len(x), M)
+        xs = np.arange(1, 29).reshape(7, 4)
+        violations = []
+        for x in xs:
+            violations.append(pc.violation(x))
+        np.testing.assert_allclose(pc.violation(xs.T), np.array(violations).T)
+
+        pc = _ConstraintWrapper(LinearConstraint(csr_matrix(A), -np.inf, 0),
+                                x0)
+        assert (pc.violation(x0) > 0).any()
+        assert (pc.violation([-10, 2, -10, 4]) == 0).all()
+
+        def fun(x):
+            return A.dot(x)
+
+        nonlinear = NonlinearConstraint(fun, -np.inf, 0)
+        pc = _ConstraintWrapper(nonlinear, [-10, 2, -10, 4])
+        assert (pc.violation(x0) > 0).any()
+        assert (pc.violation([-10, 2, -10, 4]) == 0).all()
+
+    def test_constraint_wrapper_violation(self):
+        def cons_f(x):
+            # written in vectorised form to accept an array of (N, S)
+            # returning (M, S)
+            # where N is the number of parameters,
+            # S is the number of solution vectors to be examined,
+            # and M is the number of constraint components
+            return np.array([x[0] ** 2 + x[1],
+                             x[0] ** 2 - x[1]])
+
+        nlc = NonlinearConstraint(cons_f, [-1, -0.8500], [2, 2])
+        pc = _ConstraintWrapper(nlc, [0.5, 1])
+        assert np.size(pc.bounds[0]) == 2
+
+        xs = [(0.5, 1), (0.5, 1.2), (1.2, 1.2), (0.1, -1.2), (0.1, 2.0)]
+        vs = [(0, 0), (0, 0.1), (0.64, 0), (0.19, 0), (0.01, 1.14)]
+
+        for x, v in zip(xs, vs):
+            assert_allclose(pc.violation(x), v)
+
+        # now check that we can vectorize the constraint wrapper
+        assert_allclose(pc.violation(np.array(xs).T),
+                        np.array(vs).T)
+        assert pc.fun(np.array(xs).T).shape == (2, len(xs))
+        assert pc.violation(np.array(xs).T).shape == (2, len(xs))
+        assert pc.num_constr == 2
+        assert pc.parameter_count == 2
+
+    def test_matrix_linear_constraint(self):
+        # gh20041 supplying an np.matrix to construct a LinearConstraint caused
+        # _ConstraintWrapper to start returning constraint violations of the
+        # wrong shape.
+        with suppress_warnings() as sup:
+            sup.filter(PendingDeprecationWarning)
+            matrix = np.matrix([[1, 1, 1, 1.],
+                                [2, 2, 2, 2.]])
+        lc = LinearConstraint(matrix, 0, 1)
+        x0 = np.ones(4)
+        cw = _ConstraintWrapper(lc, x0)
+        # the shape of the constraint violation should be the same as the number
+        # of constraints applied.
+        assert cw.violation(x0).shape == (2,)
+
+        # let's try a vectorised violation call.
+        xtrial = np.arange(4 * 5).reshape(4, 5)
+        assert cw.violation(xtrial).shape == (2, 5)
+
+
+    def test_L1(self):
+        # Lampinen ([5]) test problem 1
+
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = np.sum(5*x[1:5]) - 5*x[1:5]@x[1:5] - np.sum(x[5:])
+            return fun
+
+        A = np.zeros((10, 14))  # 1-indexed to match reference
+        A[1, [1, 2, 10, 11]] = 2, 2, 1, 1
+        A[2, [1, 10]] = -8, 1
+        A[3, [4, 5, 10]] = -2, -1, 1
+        A[4, [1, 3, 10, 11]] = 2, 2, 1, 1
+        A[5, [2, 11]] = -8, 1
+        A[6, [6, 7, 11]] = -2, -1, 1
+        A[7, [2, 3, 11, 12]] = 2, 2, 1, 1
+        A[8, [3, 12]] = -8, 1
+        A[9, [8, 9, 12]] = -2, -1, 1
+        A = A[1:, 1:]
+
+        b = np.array([10, 0, 0, 10, 0, 0, 10, 0, 0])
+
+        L = LinearConstraint(A, -np.inf, b)
+
+        bounds = [(0, 1)]*9 + [(0, 100)]*3 + [(0, 1)]
+
+        # using a lower popsize to speed the test up
+        res = differential_evolution(f, bounds, strategy='best1bin', seed=1234,
+                                     constraints=(L), popsize=2)
+
+        x_opt = (1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 3, 1)
+        f_opt = -15
+
+        assert_allclose(f(x_opt), f_opt, atol=6e-4)
+        assert res.success
+        assert_allclose(res.x, x_opt, atol=6e-4)
+        assert_allclose(res.fun, f_opt, atol=5e-3)
+        assert_(np.all([email protected] <= b))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+        # now repeat the same solve, using the same overall constraints,
+        # but using a sparse matrix for the LinearConstraint instead of an
+        # array
+
+        L = LinearConstraint(csr_matrix(A), -np.inf, b)
+
+        # using a lower popsize to speed the test up
+        res = differential_evolution(f, bounds, strategy='best1bin', seed=1234,
+                                     constraints=(L), popsize=2)
+
+        assert_allclose(f(x_opt), f_opt)
+        assert res.success
+        assert_allclose(res.x, x_opt, atol=5e-4)
+        assert_allclose(res.fun, f_opt, atol=5e-3)
+        assert_(np.all([email protected] <= b))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+        # now repeat the same solve, using the same overall constraints,
+        # but specify half the constraints in terms of LinearConstraint,
+        # and the other half by NonlinearConstraint
+        def c1(x):
+            x = np.hstack(([0], x))
+            return [2*x[2] + 2*x[3] + x[11] + x[12],
+                    -8*x[3] + x[12]]
+
+        def c2(x):
+            x = np.hstack(([0], x))
+            return -2*x[8] - x[9] + x[12]
+
+        L = LinearConstraint(A[:5, :], -np.inf, b[:5])
+        L2 = LinearConstraint(A[5:6, :], -np.inf, b[5:6])
+        N = NonlinearConstraint(c1, -np.inf, b[6:8])
+        N2 = NonlinearConstraint(c2, -np.inf, b[8:9])
+        constraints = (L, N, L2, N2)
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning)
+            res = differential_evolution(f, bounds, strategy='rand1bin',
+                                         seed=1234, constraints=constraints,
+                                         popsize=2)
+
+        assert_allclose(res.x, x_opt, atol=6e-4)
+        assert_allclose(res.fun, f_opt, atol=5e-3)
+        assert_(np.all([email protected] <= b))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L2(self):
+        # Lampinen ([5]) test problem 2
+
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = ((x[1]-10)**2 + 5*(x[2]-12)**2 + x[3]**4 + 3*(x[4]-11)**2 +
+                   10*x[5]**6 + 7*x[6]**2 + x[7]**4 - 4*x[6]*x[7] - 10*x[6] -
+                   8*x[7])
+            return fun
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [127 - 2*x[1]**2 - 3*x[2]**4 - x[3] - 4*x[4]**2 - 5*x[5],
+                    196 - 23*x[1] - x[2]**2 - 6*x[6]**2 + 8*x[7],
+                    282 - 7*x[1] - 3*x[2] - 10*x[3]**2 - x[4] + x[5],
+                    -4*x[1]**2 - x[2]**2 + 3*x[1]*x[2] - 2*x[3]**2 -
+                    5*x[6] + 11*x[7]]
+
+        N = NonlinearConstraint(c1, 0, np.inf)
+        bounds = [(-10, 10)]*7
+        constraints = (N)
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning)
+            res = differential_evolution(f, bounds, strategy='rand1bin',
+                                         seed=1234, constraints=constraints)
+
+        f_opt = 680.6300599487869
+        x_opt = (2.330499, 1.951372, -0.4775414, 4.365726,
+                 -0.6244870, 1.038131, 1.594227)
+
+        assert_allclose(f(x_opt), f_opt)
+        assert_allclose(res.fun, f_opt)
+        assert_allclose(res.x, x_opt, atol=1e-5)
+        assert res.success
+        assert_(np.all(np.array(c1(res.x)) >= 0))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L3(self):
+        # Lampinen ([5]) test problem 3
+
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = (x[1]**2 + x[2]**2 + x[1]*x[2] - 14*x[1] - 16*x[2] +
+                   (x[3]-10)**2 + 4*(x[4]-5)**2 + (x[5]-3)**2 + 2*(x[6]-1)**2 +
+                   5*x[7]**2 + 7*(x[8]-11)**2 + 2*(x[9]-10)**2 +
+                   (x[10] - 7)**2 + 45
+                   )
+            return fun  # maximize
+
+        A = np.zeros((4, 11))
+        A[1, [1, 2, 7, 8]] = -4, -5, 3, -9
+        A[2, [1, 2, 7, 8]] = -10, 8, 17, -2
+        A[3, [1, 2, 9, 10]] = 8, -2, -5, 2
+        A = A[1:, 1:]
+        b = np.array([-105, 0, -12])
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [3*x[1] - 6*x[2] - 12*(x[9]-8)**2 + 7*x[10],
+                    -3*(x[1]-2)**2 - 4*(x[2]-3)**2 - 2*x[3]**2 + 7*x[4] + 120,
+                    -x[1]**2 - 2*(x[2]-2)**2 + 2*x[1]*x[2] - 14*x[5] + 6*x[6],
+                    -5*x[1]**2 - 8*x[2] - (x[3]-6)**2 + 2*x[4] + 40,
+                    -0.5*(x[1]-8)**2 - 2*(x[2]-4)**2 - 3*x[5]**2 + x[6] + 30]
+
+        L = LinearConstraint(A, b, np.inf)
+        N = NonlinearConstraint(c1, 0, np.inf)
+        bounds = [(-10, 10)]*10
+        constraints = (L, N)
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning)
+            res = differential_evolution(f, bounds, seed=1234,
+                                         constraints=constraints, popsize=3)
+
+        x_opt = (2.171996, 2.363683, 8.773926, 5.095984, 0.9906548,
+                 1.430574, 1.321644, 9.828726, 8.280092, 8.375927)
+        f_opt = 24.3062091
+
+        assert_allclose(f(x_opt), f_opt, atol=1e-5)
+        assert_allclose(res.x, x_opt, atol=1e-6)
+        assert_allclose(res.fun, f_opt, atol=1e-5)
+        assert res.success
+        assert_(np.all(A @ res.x >= b))
+        assert_(np.all(np.array(c1(res.x)) >= 0))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L4(self):
+        # Lampinen ([5]) test problem 4
+        def f(x):
+            return np.sum(x[:3])
+
+        A = np.zeros((4, 9))
+        A[1, [4, 6]] = 0.0025, 0.0025
+        A[2, [5, 7, 4]] = 0.0025, 0.0025, -0.0025
+        A[3, [8, 5]] = 0.01, -0.01
+        A = A[1:, 1:]
+        b = np.array([1, 1, 1])
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [x[1]*x[6] - 833.33252*x[4] - 100*x[1] + 83333.333,
+                    x[2]*x[7] - 1250*x[5] - x[2]*x[4] + 1250*x[4],
+                    x[3]*x[8] - 1250000 - x[3]*x[5] + 2500*x[5]]
+
+        L = LinearConstraint(A, -np.inf, 1)
+        N = NonlinearConstraint(c1, 0, np.inf)
+
+        bounds = [(100, 10000)] + [(1000, 10000)]*2 + [(10, 1000)]*5
+        constraints = (L, N)
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning)
+            res = differential_evolution(f, bounds, strategy='rand1bin',
+                                     seed=1234, constraints=constraints,
+                                     popsize=3)
+
+        f_opt = 7049.248
+
+        x_opt = [579.306692, 1359.97063, 5109.9707, 182.0177, 295.601172,
+                217.9823, 286.416528, 395.601172]
+
+        assert_allclose(f(x_opt), f_opt, atol=0.001)
+        assert_allclose(res.fun, f_opt, atol=0.001)
+
+        # use higher tol here for 32-bit Windows, see gh-11693
+        if (platform.system() == 'Windows' and np.dtype(np.intp).itemsize < 8):
+            assert_allclose(res.x, x_opt, rtol=2.4e-6, atol=0.0035)
+        else:
+            # tolerance determined from macOS + MKL failure, see gh-12701
+            assert_allclose(res.x, x_opt, rtol=5e-6, atol=0.0024)
+
+        assert res.success
+        assert_(np.all(A @ res.x <= b))
+        assert_(np.all(np.array(c1(res.x)) >= 0))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L5(self):
+        # Lampinen ([5]) test problem 5
+
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = (np.sin(2*np.pi*x[1])**3*np.sin(2*np.pi*x[2]) /
+                   (x[1]**3*(x[1]+x[2])))
+            return -fun  # maximize
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [x[1]**2 - x[2] + 1,
+                    1 - x[1] + (x[2]-4)**2]
+
+        N = NonlinearConstraint(c1, -np.inf, 0)
+        bounds = [(0, 10)]*2
+        constraints = (N)
+
+        res = differential_evolution(f, bounds, strategy='rand1bin', seed=1234,
+                                     constraints=constraints)
+
+        x_opt = (1.22797135, 4.24537337)
+        f_opt = -0.095825
+        assert_allclose(f(x_opt), f_opt, atol=2e-5)
+        assert_allclose(res.fun, f_opt, atol=1e-4)
+        assert res.success
+        assert_(np.all(np.array(c1(res.x)) <= 0))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L6(self):
+        # Lampinen ([5]) test problem 6
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = (x[1]-10)**3 + (x[2] - 20)**3
+            return fun
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [(x[1]-5)**2 + (x[2] - 5)**2 - 100,
+                    -(x[1]-6)**2 - (x[2] - 5)**2 + 82.81]
+
+        N = NonlinearConstraint(c1, 0, np.inf)
+        bounds = [(13, 100), (0, 100)]
+        constraints = (N)
+        res = differential_evolution(f, bounds, strategy='rand1bin', seed=1234,
+                                     constraints=constraints, tol=1e-7)
+        x_opt = (14.095, 0.84296)
+        f_opt = -6961.814744
+
+        assert_allclose(f(x_opt), f_opt, atol=1e-6)
+        assert_allclose(res.fun, f_opt, atol=0.001)
+        assert_allclose(res.x, x_opt, atol=1e-4)
+        assert res.success
+        assert_(np.all(np.array(c1(res.x)) >= 0))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L7(self):
+        # Lampinen ([5]) test problem 7
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = (5.3578547*x[3]**2 + 0.8356891*x[1]*x[5] +
+                   37.293239*x[1] - 40792.141)
+            return fun
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [
+                    85.334407 + 0.0056858*x[2]*x[5] + 0.0006262*x[1]*x[4] -
+                    0.0022053*x[3]*x[5],
+
+                    80.51249 + 0.0071317*x[2]*x[5] + 0.0029955*x[1]*x[2] +
+                    0.0021813*x[3]**2,
+
+                    9.300961 + 0.0047026*x[3]*x[5] + 0.0012547*x[1]*x[3] +
+                    0.0019085*x[3]*x[4]
+                    ]
+
+        N = NonlinearConstraint(c1, [0, 90, 20], [92, 110, 25])
+
+        bounds = [(78, 102), (33, 45)] + [(27, 45)]*3
+        constraints = (N)
+
+        res = differential_evolution(f, bounds, strategy='rand1bin', seed=1234,
+                                     constraints=constraints)
+
+        # using our best solution, rather than Lampinen/Koziel. Koziel solution
+        # doesn't satisfy constraints, Lampinen f_opt just plain wrong.
+        x_opt = [78.00000686, 33.00000362, 29.99526064, 44.99999971,
+                 36.77579979]
+
+        f_opt = -30665.537578
+
+        assert_allclose(f(x_opt), f_opt)
+        assert_allclose(res.x, x_opt, atol=1e-3)
+        assert_allclose(res.fun, f_opt, atol=1e-3)
+
+        assert res.success
+        assert_(np.all(np.array(c1(res.x)) >= np.array([0, 90, 20])))
+        assert_(np.all(np.array(c1(res.x)) <= np.array([92, 110, 25])))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    @pytest.mark.slow
+    @pytest.mark.xfail(platform.machine() == 'ppc64le',
+                       reason="fails on ppc64le")
+    def test_L8(self):
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            fun = 3*x[1] + 0.000001*x[1]**3 + 2*x[2] + 0.000002/3*x[2]**3
+            return fun
+
+        A = np.zeros((3, 5))
+        A[1, [4, 3]] = 1, -1
+        A[2, [3, 4]] = 1, -1
+        A = A[1:, 1:]
+        b = np.array([-.55, -.55])
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [
+                    1000*np.sin(-x[3]-0.25) + 1000*np.sin(-x[4]-0.25) +
+                    894.8 - x[1],
+                    1000*np.sin(x[3]-0.25) + 1000*np.sin(x[3]-x[4]-0.25) +
+                    894.8 - x[2],
+                    1000*np.sin(x[4]-0.25) + 1000*np.sin(x[4]-x[3]-0.25) +
+                    1294.8
+                    ]
+        L = LinearConstraint(A, b, np.inf)
+        N = NonlinearConstraint(c1, np.full(3, -0.001), np.full(3, 0.001))
+
+        bounds = [(0, 1200)]*2+[(-.55, .55)]*2
+        constraints = (L, N)
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning)
+            # original Lampinen test was with rand1bin, but that takes a
+            # huge amount of CPU time. Changing strategy to best1bin speeds
+            # things up a lot
+            res = differential_evolution(f, bounds, strategy='best1bin',
+                                         seed=1234, constraints=constraints,
+                                         maxiter=5000)
+
+        x_opt = (679.9453, 1026.067, 0.1188764, -0.3962336)
+        f_opt = 5126.4981
+
+        assert_allclose(f(x_opt), f_opt, atol=1e-3)
+        assert_allclose(res.x[:2], x_opt[:2], atol=2e-3)
+        assert_allclose(res.x[2:], x_opt[2:], atol=2e-3)
+        assert_allclose(res.fun, f_opt, atol=2e-2)
+        assert res.success
+        assert_(np.all([email protected] >= b))
+        assert_(np.all(np.array(c1(res.x)) >= -0.001))
+        assert_(np.all(np.array(c1(res.x)) <= 0.001))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_L9(self):
+        # Lampinen ([5]) test problem 9
+
+        def f(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return x[1]**2 + (x[2]-1)**2
+
+        def c1(x):
+            x = np.hstack(([0], x))  # 1-indexed to match reference
+            return [x[2] - x[1]**2]
+
+        N = NonlinearConstraint(c1, [-.001], [0.001])
+
+        bounds = [(-1, 1)]*2
+        constraints = (N)
+        res = differential_evolution(f, bounds, strategy='rand1bin', seed=1234,
+                                     constraints=constraints)
+
+        x_opt = [np.sqrt(2)/2, 0.5]
+        f_opt = 0.75
+
+        assert_allclose(f(x_opt), f_opt)
+        assert_allclose(np.abs(res.x), x_opt, atol=1e-3)
+        assert_allclose(res.fun, f_opt, atol=1e-3)
+        assert res.success
+        assert_(np.all(np.array(c1(res.x)) >= -0.001))
+        assert_(np.all(np.array(c1(res.x)) <= 0.001))
+        assert_(np.all(res.x >= np.array(bounds)[:, 0]))
+        assert_(np.all(res.x <= np.array(bounds)[:, 1]))
+
+    def test_integrality(self):
+        # test fitting discrete distribution to data
+        rng = np.random.default_rng(6519843218105)
+        dist = stats.nbinom
+        shapes = (5, 0.5)
+        x = dist.rvs(*shapes, size=10000, random_state=rng)
+
+        def func(p, *args):
+            dist, x = args
+            # negative log-likelihood function
+            ll = -np.log(dist.pmf(x, *p)).sum(axis=-1)
+            if np.isnan(ll):  # occurs when x is outside of support
+                ll = np.inf  # we don't want that
+            return ll
+
+        integrality = [True, False]
+        bounds = [(1, 18), (0, 0.95)]
+
+        res = differential_evolution(func, bounds, args=(dist, x),
+                                     integrality=integrality, polish=False,
+                                     seed=rng)
+        # tolerance has to be fairly relaxed for the second parameter
+        # because we're fitting a distribution to random variates.
+        assert res.x[0] == 5
+        assert_allclose(res.x, shapes, rtol=0.025)
+
+        # check that we can still use integrality constraints with polishing
+        res2 = differential_evolution(func, bounds, args=(dist, x),
+                                      integrality=integrality, polish=True,
+                                      seed=rng)
+
+        def func2(p, *args):
+            n, dist, x = args
+            return func(np.array([n, p[0]]), dist, x)
+
+        # compare the DE derived solution to an LBFGSB solution (that doesn't
+        # have to find the integral values). Note we're setting x0 to be the
+        # output from the first DE result, thereby making the polishing step
+        # and this minimisation pretty much equivalent.
+        LBFGSB = minimize(func2, res2.x[1], args=(5, dist, x),
+                          bounds=[(0, 0.95)])
+        assert_allclose(res2.x[1], LBFGSB.x)
+        assert res2.fun <= res.fun
+
+    def test_integrality_limits(self):
+        def f(x):
+            return x
+
+        integrality = [True, False, True]
+        bounds = [(0.2, 1.1), (0.9, 2.2), (3.3, 4.9)]
+
+        # no integrality constraints
+        solver = DifferentialEvolutionSolver(f, bounds=bounds, polish=False,
+                                             integrality=False)
+        assert_allclose(solver.limits[0], [0.2, 0.9, 3.3])
+        assert_allclose(solver.limits[1], [1.1, 2.2, 4.9])
+
+        # with integrality constraints
+        solver = DifferentialEvolutionSolver(f, bounds=bounds, polish=False,
+                                             integrality=integrality)
+        assert_allclose(solver.limits[0], [0.5, 0.9, 3.5])
+        assert_allclose(solver.limits[1], [1.5, 2.2, 4.5])
+        assert_equal(solver.integrality, [True, False, True])
+        assert solver.polish is False
+
+        bounds = [(-1.2, -0.9), (0.9, 2.2), (-10.3, 4.1)]
+        solver = DifferentialEvolutionSolver(f, bounds=bounds, polish=False,
+                                             integrality=integrality)
+        assert_allclose(solver.limits[0], [-1.5, 0.9, -10.5])
+        assert_allclose(solver.limits[1], [-0.5, 2.2, 4.5])
+
+        # A lower bound of -1.2 is converted to
+        # np.nextafter(np.ceil(-1.2) - 0.5, np.inf)
+        # with a similar process to the upper bound. Check that the
+        # conversions work
+        assert_allclose(np.round(solver.limits[0]), [-1.0, 1.0, -10.0])
+        assert_allclose(np.round(solver.limits[1]), [-1.0, 2.0, 4.0])
+
+        bounds = [(-10.2, -8.1), (0.9, 2.2), (-10.9, -9.9999)]
+        solver = DifferentialEvolutionSolver(f, bounds=bounds, polish=False,
+                                             integrality=integrality)
+        assert_allclose(solver.limits[0], [-10.5, 0.9, -10.5])
+        assert_allclose(solver.limits[1], [-8.5, 2.2, -9.5])
+
+        bounds = [(-10.2, -10.1), (0.9, 2.2), (-10.9, -9.9999)]
+        with pytest.raises(ValueError, match='One of the integrality'):
+            DifferentialEvolutionSolver(f, bounds=bounds, polish=False,
+                                        integrality=integrality)
+
+    def test_vectorized(self):
+        def quadratic(x):
+            return np.sum(x**2)
+
+        def quadratic_vec(x):
+            return np.sum(x**2, axis=0)
+
+        # A vectorized function needs to accept (len(x), S) and return (S,)
+        with pytest.raises(RuntimeError, match='The vectorized function'):
+            differential_evolution(quadratic, self.bounds,
+                                   vectorized=True, updating='deferred')
+
+        # vectorized overrides the updating keyword, check for warning
+        with warns(UserWarning, match="differential_evolution: the 'vector"):
+            differential_evolution(quadratic_vec, self.bounds,
+                                   vectorized=True)
+
+        # vectorized defers to the workers keyword, check for warning
+        with warns(UserWarning, match="differential_evolution: the 'workers"):
+            differential_evolution(quadratic_vec, self.bounds,
+                                   vectorized=True, workers=map,
+                                   updating='deferred')
+
+        ncalls = [0]
+
+        def rosen_vec(x):
+            ncalls[0] += 1
+            return rosen(x)
+
+        bounds = [(0, 10), (0, 10)]
+        res1 = differential_evolution(rosen, bounds, updating='deferred',
+                                      seed=1)
+        res2 = differential_evolution(rosen_vec, bounds, vectorized=True,
+                                      updating='deferred', seed=1)
+
+        # the two minimisation runs should be functionally equivalent
+        assert_allclose(res1.x, res2.x)
+        assert ncalls[0] == res2.nfev
+        assert res1.nit == res2.nit
+
+    def test_vectorized_constraints(self):
+        def constr_f(x):
+            return np.array([x[0] + x[1]])
+
+        def constr_f2(x):
+            return np.array([x[0]**2 + x[1], x[0] - x[1]])
+
+        nlc1 = NonlinearConstraint(constr_f, -np.inf, 1.9)
+        nlc2 = NonlinearConstraint(constr_f2, (0.9, 0.5), (2.0, 2.0))
+
+        def rosen_vec(x):
+            # accept an (len(x0), S) array, returning a (S,) array
+            v = 100 * (x[1:] - x[:-1]**2.0)**2.0
+            v += (1 - x[:-1])**2.0
+            return np.squeeze(v)
+
+        bounds = [(0, 10), (0, 10)]
+
+        res1 = differential_evolution(rosen, bounds, updating='deferred',
+                                      seed=1, constraints=[nlc1, nlc2],
+                                      polish=False)
+        res2 = differential_evolution(rosen_vec, bounds, vectorized=True,
+                                      updating='deferred', seed=1,
+                                      constraints=[nlc1, nlc2],
+                                      polish=False)
+        # the two minimisation runs should be functionally equivalent
+        assert_allclose(res1.x, res2.x)
+
+    def test_constraint_violation_error_message(self):
+
+        def func(x):
+            return np.cos(x[0]) + np.sin(x[1])
+
+        # Intentionally infeasible constraints.
+        c0 = NonlinearConstraint(lambda x: x[1] - (x[0]-1)**2, 0, np.inf)
+        c1 = NonlinearConstraint(lambda x: x[1] + x[0]**2, -np.inf, 0)
+
+        result = differential_evolution(func,
+                                        bounds=[(-1, 2), (-1, 1)],
+                                        constraints=[c0, c1],
+                                        maxiter=10,
+                                        polish=False,
+                                        seed=864197532)
+        assert result.success is False
+        # The numerical value in the error message might be sensitive to
+        # changes in the implementation.  It can be updated if the code is
+        # changed.  The essential part of the test is that there is a number
+        # after the '=', so if necessary, the text could be reduced to, say,
+        # "MAXCV = 0.".
+        assert "MAXCV = 0.414" in result.message
+
+    def test_strategy_fn(self):
+        # examines ability to customize strategy by mimicking one of the
+        # in-built strategies and comparing to the actual in-built strategy.
+        parameter_count = 4
+        popsize = 10
+        bounds = [(0, 10.)] * parameter_count
+        total_popsize = parameter_count * popsize
+        mutation = 0.8
+        recombination = 0.7
+
+        def custom_strategy_fn(candidate, population, rng=None):
+            trial = np.copy(population[candidate])
+            fill_point = rng.choice(parameter_count)
+
+            pool = np.arange(total_popsize)
+            rng.shuffle(pool)
+
+            idxs = []
+            while len(idxs) < 2 and len(pool) > 0:
+                idx = pool[0]
+                pool = pool[1:]
+                if idx != candidate:
+                    idxs.append(idx)
+
+            r0, r1 = idxs[:2]
+
+            bprime = (population[0] + mutation *
+                    (population[r0] - population[r1]))
+
+            crossovers = rng.uniform(size=parameter_count)
+            crossovers = crossovers < recombination
+            crossovers[fill_point] = True
+            trial = np.where(crossovers, bprime, trial)
+            return trial
+
+        solver = DifferentialEvolutionSolver(
+            rosen,
+            bounds,
+            popsize=popsize,
+            recombination=recombination,
+            mutation=mutation,
+            maxiter=2,
+            strategy=custom_strategy_fn,
+            seed=10,
+            polish=False
+        )
+        assert solver.strategy is custom_strategy_fn
+        res = solver.solve()
+
+        res2 = differential_evolution(
+            rosen,
+            bounds,
+            mutation=mutation,
+            popsize=popsize,
+            recombination=recombination,
+            maxiter=2,
+            strategy='best1bin',
+            polish=False,
+            seed=10
+        )
+        assert_allclose(res.population, res2.population)
+        assert_allclose(res.x, res2.x)
+
+        def custom_strategy_fn(candidate, population, rng=None):
+            return np.array([1.0, 2.0])
+
+        with pytest.raises(RuntimeError, match="strategy*"):
+            differential_evolution(
+                rosen,
+                bounds,
+                strategy=custom_strategy_fn
+            )

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__dual_annealing.py

@@ -0,0 +1,379 @@
+# Dual annealing unit tests implementation.
+# Copyright (c) 2018 Sylvain Gubian <[email protected]>,
+# Yang Xiang <[email protected]>
+# Author: Sylvain Gubian, PMP S.A.
+"""
+Unit tests for the dual annealing global optimizer
+"""
+from scipy.optimize import dual_annealing, Bounds
+
+from scipy.optimize._dual_annealing import EnergyState
+from scipy.optimize._dual_annealing import LocalSearchWrapper
+from scipy.optimize._dual_annealing import ObjectiveFunWrapper
+from scipy.optimize._dual_annealing import StrategyChain
+from scipy.optimize._dual_annealing import VisitingDistribution
+from scipy.optimize import rosen, rosen_der
+import pytest
+import numpy as np
+from numpy.testing import assert_equal, assert_allclose, assert_array_less
+from pytest import raises as assert_raises
+from scipy._lib._util import check_random_state
+
+
+class TestDualAnnealing:
+
+    def setup_method(self):
+        # A function that returns always infinity for initialization tests
+        self.weirdfunc = lambda x: np.inf
+        # 2-D bounds for testing function
+        self.ld_bounds = [(-5.12, 5.12)] * 2
+        # 4-D bounds for testing function
+        self.hd_bounds = self.ld_bounds * 4
+        # Number of values to be generated for testing visit function
+        self.nbtestvalues = 5000
+        self.high_temperature = 5230
+        self.low_temperature = 0.1
+        self.qv = 2.62
+        self.seed = 1234
+        self.rs = check_random_state(self.seed)
+        self.nb_fun_call = 0
+        self.ngev = 0
+
+    def callback(self, x, f, context):
+        # For testing callback mechanism. Should stop for e <= 1 as
+        # the callback function returns True
+        if f <= 1.0:
+            return True
+
+    def func(self, x, args=()):
+        # Using Rastrigin function for performing tests
+        if args:
+            shift = args
+        else:
+            shift = 0
+        y = np.sum((x - shift) ** 2 - 10 * np.cos(2 * np.pi * (
+            x - shift))) + 10 * np.size(x) + shift
+        self.nb_fun_call += 1
+        return y
+
+    def rosen_der_wrapper(self, x, args=()):
+        self.ngev += 1
+        return rosen_der(x, *args)
+
+    # FIXME: there are some discontinuities in behaviour as a function of `qv`,
+    #        this needs investigating - see gh-12384
+    @pytest.mark.parametrize('qv', [1.1, 1.41, 2, 2.62, 2.9])
+    def test_visiting_stepping(self, qv):
+        lu = list(zip(*self.ld_bounds))
+        lower = np.array(lu[0])
+        upper = np.array(lu[1])
+        dim = lower.size
+        vd = VisitingDistribution(lower, upper, qv, self.rs)
+        values = np.zeros(dim)
+        x_step_low = vd.visiting(values, 0, self.high_temperature)
+        # Make sure that only the first component is changed
+        assert_equal(np.not_equal(x_step_low, 0), True)
+        values = np.zeros(dim)
+        x_step_high = vd.visiting(values, dim, self.high_temperature)
+        # Make sure that component other than at dim has changed
+        assert_equal(np.not_equal(x_step_high[0], 0), True)
+
+    @pytest.mark.parametrize('qv', [2.25, 2.62, 2.9])
+    def test_visiting_dist_high_temperature(self, qv):
+        lu = list(zip(*self.ld_bounds))
+        lower = np.array(lu[0])
+        upper = np.array(lu[1])
+        vd = VisitingDistribution(lower, upper, qv, self.rs)
+        # values = np.zeros(self.nbtestvalues)
+        # for i in np.arange(self.nbtestvalues):
+        #     values[i] = vd.visit_fn(self.high_temperature)
+        values = vd.visit_fn(self.high_temperature, self.nbtestvalues)
+
+        # Visiting distribution is a distorted version of Cauchy-Lorentz
+        # distribution, and as no 1st and higher moments (no mean defined,
+        # no variance defined).
+        # Check that big tails values are generated
+        assert_array_less(np.min(values), 1e-10)
+        assert_array_less(1e+10, np.max(values))
+
+    def test_reset(self):
+        owf = ObjectiveFunWrapper(self.weirdfunc)
+        lu = list(zip(*self.ld_bounds))
+        lower = np.array(lu[0])
+        upper = np.array(lu[1])
+        es = EnergyState(lower, upper)
+        assert_raises(ValueError, es.reset, owf, check_random_state(None))
+
+    def test_low_dim(self):
+        ret = dual_annealing(
+            self.func, self.ld_bounds, seed=self.seed)
+        assert_allclose(ret.fun, 0., atol=1e-12)
+        assert ret.success
+
+    def test_high_dim(self):
+        ret = dual_annealing(self.func, self.hd_bounds, seed=self.seed)
+        assert_allclose(ret.fun, 0., atol=1e-12)
+        assert ret.success
+
+    def test_low_dim_no_ls(self):
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             no_local_search=True, seed=self.seed)
+        assert_allclose(ret.fun, 0., atol=1e-4)
+
+    def test_high_dim_no_ls(self):
+        ret = dual_annealing(self.func, self.hd_bounds,
+                             no_local_search=True, seed=self.seed)
+        assert_allclose(ret.fun, 0., atol=1e-4)
+
+    def test_nb_fun_call(self):
+        ret = dual_annealing(self.func, self.ld_bounds, seed=self.seed)
+        assert_equal(self.nb_fun_call, ret.nfev)
+
+    def test_nb_fun_call_no_ls(self):
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             no_local_search=True, seed=self.seed)
+        assert_equal(self.nb_fun_call, ret.nfev)
+
+    def test_max_reinit(self):
+        assert_raises(ValueError, dual_annealing, self.weirdfunc,
+                      self.ld_bounds)
+
+    def test_reproduce(self):
+        res1 = dual_annealing(self.func, self.ld_bounds, seed=self.seed)
+        res2 = dual_annealing(self.func, self.ld_bounds, seed=self.seed)
+        res3 = dual_annealing(self.func, self.ld_bounds, seed=self.seed)
+        # If we have reproducible results, x components found has to
+        # be exactly the same, which is not the case with no seeding
+        assert_equal(res1.x, res2.x)
+        assert_equal(res1.x, res3.x)
+
+    def test_rand_gen(self):
+        # check that np.random.Generator can be used (numpy >= 1.17)
+        # obtain a np.random.Generator object
+        rng = np.random.default_rng(1)
+
+        res1 = dual_annealing(self.func, self.ld_bounds, seed=rng)
+        # seed again
+        rng = np.random.default_rng(1)
+        res2 = dual_annealing(self.func, self.ld_bounds, seed=rng)
+        # If we have reproducible results, x components found has to
+        # be exactly the same, which is not the case with no seeding
+        assert_equal(res1.x, res2.x)
+
+    def test_bounds_integrity(self):
+        wrong_bounds = [(-5.12, 5.12), (1, 0), (5.12, 5.12)]
+        assert_raises(ValueError, dual_annealing, self.func,
+                      wrong_bounds)
+
+    def test_bound_validity(self):
+        invalid_bounds = [(-5, 5), (-np.inf, 0), (-5, 5)]
+        assert_raises(ValueError, dual_annealing, self.func,
+                      invalid_bounds)
+        invalid_bounds = [(-5, 5), (0, np.inf), (-5, 5)]
+        assert_raises(ValueError, dual_annealing, self.func,
+                      invalid_bounds)
+        invalid_bounds = [(-5, 5), (0, np.nan), (-5, 5)]
+        assert_raises(ValueError, dual_annealing, self.func,
+                      invalid_bounds)
+
+    def test_deprecated_local_search_options_bounds(self):
+        def func(x):
+            return np.sum((x - 5) * (x - 1))
+        bounds = list(zip([-6, -5], [6, 5]))
+        # Test bounds can be passed (see gh-10831)
+
+        with pytest.warns(RuntimeWarning, match=r"Method CG cannot handle "):
+            dual_annealing(
+                func,
+                bounds=bounds,
+                minimizer_kwargs={"method": "CG", "bounds": bounds})
+
+    def test_minimizer_kwargs_bounds(self):
+        def func(x):
+            return np.sum((x - 5) * (x - 1))
+        bounds = list(zip([-6, -5], [6, 5]))
+        # Test bounds can be passed (see gh-10831)
+        dual_annealing(
+            func,
+            bounds=bounds,
+            minimizer_kwargs={"method": "SLSQP", "bounds": bounds})
+
+        with pytest.warns(RuntimeWarning, match=r"Method CG cannot handle "):
+            dual_annealing(
+                func,
+                bounds=bounds,
+                minimizer_kwargs={"method": "CG", "bounds": bounds})
+
+    def test_max_fun_ls(self):
+        ret = dual_annealing(self.func, self.ld_bounds, maxfun=100,
+                             seed=self.seed)
+
+        ls_max_iter = min(max(
+            len(self.ld_bounds) * LocalSearchWrapper.LS_MAXITER_RATIO,
+            LocalSearchWrapper.LS_MAXITER_MIN),
+            LocalSearchWrapper.LS_MAXITER_MAX)
+        assert ret.nfev <= 100 + ls_max_iter
+        assert not ret.success
+
+    def test_max_fun_no_ls(self):
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             no_local_search=True, maxfun=500, seed=self.seed)
+        assert ret.nfev <= 500
+        assert not ret.success
+
+    def test_maxiter(self):
+        ret = dual_annealing(self.func, self.ld_bounds, maxiter=700,
+                             seed=self.seed)
+        assert ret.nit <= 700
+
+    # Testing that args are passed correctly for dual_annealing
+    def test_fun_args_ls(self):
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             args=((3.14159,)), seed=self.seed)
+        assert_allclose(ret.fun, 3.14159, atol=1e-6)
+
+    # Testing that args are passed correctly for pure simulated annealing
+    def test_fun_args_no_ls(self):
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             args=((3.14159, )), no_local_search=True,
+                             seed=self.seed)
+        assert_allclose(ret.fun, 3.14159, atol=1e-4)
+
+    def test_callback_stop(self):
+        # Testing that callback make the algorithm stop for
+        # fun value <= 1.0 (see callback method)
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             callback=self.callback, seed=self.seed)
+        assert ret.fun <= 1.0
+        assert 'stop early' in ret.message[0]
+        assert not ret.success
+
+    @pytest.mark.parametrize('method, atol', [
+        ('Nelder-Mead', 2e-5),
+        ('COBYLA', 1e-5),
+        ('Powell', 1e-8),
+        ('CG', 1e-8),
+        ('BFGS', 1e-8),
+        ('TNC', 1e-8),
+        ('SLSQP', 2e-7),
+    ])
+    def test_multi_ls_minimizer(self, method, atol):
+        ret = dual_annealing(self.func, self.ld_bounds,
+                             minimizer_kwargs=dict(method=method),
+                             seed=self.seed)
+        assert_allclose(ret.fun, 0., atol=atol)
+
+    def test_wrong_restart_temp(self):
+        assert_raises(ValueError, dual_annealing, self.func,
+                      self.ld_bounds, restart_temp_ratio=1)
+        assert_raises(ValueError, dual_annealing, self.func,
+                      self.ld_bounds, restart_temp_ratio=0)
+
+    def test_gradient_gnev(self):
+        minimizer_opts = {
+            'jac': self.rosen_der_wrapper,
+        }
+        ret = dual_annealing(rosen, self.ld_bounds,
+                             minimizer_kwargs=minimizer_opts,
+                             seed=self.seed)
+        assert ret.njev == self.ngev
+
+    def test_from_docstring(self):
+        def func(x):
+            return np.sum(x * x - 10 * np.cos(2 * np.pi * x)) + 10 * np.size(x)
+        lw = [-5.12] * 10
+        up = [5.12] * 10
+        ret = dual_annealing(func, bounds=list(zip(lw, up)), seed=1234)
+        assert_allclose(ret.x,
+                        [-4.26437714e-09, -3.91699361e-09, -1.86149218e-09,
+                         -3.97165720e-09, -6.29151648e-09, -6.53145322e-09,
+                         -3.93616815e-09, -6.55623025e-09, -6.05775280e-09,
+                         -5.00668935e-09], atol=4e-8)
+        assert_allclose(ret.fun, 0.000000, atol=5e-13)
+
+    @pytest.mark.parametrize('new_e, temp_step, accepted, accept_rate', [
+        (0, 100, 1000, 1.0097587941791923),
+        (0, 2, 1000, 1.2599210498948732),
+        (10, 100, 878, 0.8786035869128718),
+        (10, 60, 695, 0.6812920690579612),
+        (2, 100, 990, 0.9897404249173424),
+    ])
+    def test_accept_reject_probabilistic(
+            self, new_e, temp_step, accepted, accept_rate):
+        # Test accepts unconditionally with e < current_energy and
+        # probabilistically with e > current_energy
+
+        rs = check_random_state(123)
+
+        count_accepted = 0
+        iterations = 1000
+
+        accept_param = -5
+        current_energy = 1
+        for _ in range(iterations):
+            energy_state = EnergyState(lower=None, upper=None)
+            # Set energy state with current_energy, any location.
+            energy_state.update_current(current_energy, [0])
+
+            chain = StrategyChain(
+                accept_param, None, None, None, rs, energy_state)
+            # Normally this is set in run()
+            chain.temperature_step = temp_step
+
+            # Check if update is accepted.
+            chain.accept_reject(j=1, e=new_e, x_visit=[2])
+            if energy_state.current_energy == new_e:
+                count_accepted += 1
+
+        assert count_accepted == accepted
+
+        # Check accept rate
+        pqv = 1 - (1 - accept_param) * (new_e - current_energy) / temp_step
+        rate = 0 if pqv <= 0 else np.exp(np.log(pqv) / (1 - accept_param))
+
+        assert_allclose(rate, accept_rate)
+
+    def test_bounds_class(self):
+        # test that result does not depend on the bounds type
+        def func(x):
+            f = np.sum(x * x - 10 * np.cos(2 * np.pi * x)) + 10 * np.size(x)
+            return f
+        lw = [-5.12] * 5
+        up = [5.12] * 5
+
+        # Unbounded global minimum is all zeros. Most bounds below will force
+        # a DV away from unbounded minimum and be active at solution.
+        up[0] = -2.0
+        up[1] = -1.0
+        lw[3] = 1.0
+        lw[4] = 2.0
+
+        # run optimizations
+        bounds = Bounds(lw, up)
+        ret_bounds_class = dual_annealing(func, bounds=bounds, seed=1234)
+
+        bounds_old = list(zip(lw, up))
+        ret_bounds_list = dual_annealing(func, bounds=bounds_old, seed=1234)
+
+        # test that found minima, function evaluations and iterations match
+        assert_allclose(ret_bounds_class.x, ret_bounds_list.x, atol=1e-8)
+        assert_allclose(ret_bounds_class.x, np.arange(-2, 3), atol=1e-7)
+        assert_allclose(ret_bounds_list.fun, ret_bounds_class.fun, atol=1e-9)
+        assert ret_bounds_list.nfev == ret_bounds_class.nfev
+
+    def test_callable_jac_with_args_gh11052(self):
+        # dual_annealing used to fail when `jac` was callable and `args` were
+        # used; check that this is resolved. Example is from gh-11052.
+        rng = np.random.default_rng(94253637693657847462)
+        def f(x, power):
+            return np.sum(np.exp(x ** power))
+
+        def jac(x, power):
+            return np.exp(x ** power) * power * x ** (power - 1)
+
+        res1 = dual_annealing(f, args=(2, ), bounds=[[0, 1], [0, 1]], seed=rng,
+                              minimizer_kwargs=dict(method='L-BFGS-B'))
+        res2 = dual_annealing(f, args=(2, ), bounds=[[0, 1], [0, 1]], seed=rng,
+                              minimizer_kwargs=dict(method='L-BFGS-B',
+                                                    jac=jac))
+        assert_allclose(res1.fun, res2.fun, rtol=1e-6)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__linprog_clean_inputs.py

@@ -0,0 +1,310 @@
+"""
+Unit test for Linear Programming via Simplex Algorithm.
+"""
+import numpy as np
+from numpy.testing import assert_, assert_allclose, assert_equal
+from pytest import raises as assert_raises
+from scipy.optimize._linprog_util import _clean_inputs, _LPProblem
+from scipy._lib._util import VisibleDeprecationWarning
+from copy import deepcopy
+from datetime import date
+
+
+def test_aliasing():
+    """
+    Test for ensuring that no objects referred to by `lp` attributes,
+    `c`, `A_ub`, `b_ub`, `A_eq`, `b_eq`, `bounds`, have been modified
+    by `_clean_inputs` as a side effect.
+    """
+    lp = _LPProblem(
+        c=1,
+        A_ub=[[1]],
+        b_ub=[1],
+        A_eq=[[1]],
+        b_eq=[1],
+        bounds=(-np.inf, np.inf)
+    )
+    lp_copy = deepcopy(lp)
+
+    _clean_inputs(lp)
+
+    assert_(lp.c == lp_copy.c, "c modified by _clean_inputs")
+    assert_(lp.A_ub == lp_copy.A_ub, "A_ub modified by _clean_inputs")
+    assert_(lp.b_ub == lp_copy.b_ub, "b_ub modified by _clean_inputs")
+    assert_(lp.A_eq == lp_copy.A_eq, "A_eq modified by _clean_inputs")
+    assert_(lp.b_eq == lp_copy.b_eq, "b_eq modified by _clean_inputs")
+    assert_(lp.bounds == lp_copy.bounds, "bounds modified by _clean_inputs")
+
+
+def test_aliasing2():
+    """
+    Similar purpose as `test_aliasing` above.
+    """
+    lp = _LPProblem(
+        c=np.array([1, 1]),
+        A_ub=np.array([[1, 1], [2, 2]]),
+        b_ub=np.array([[1], [1]]),
+        A_eq=np.array([[1, 1]]),
+        b_eq=np.array([1]),
+        bounds=[(-np.inf, np.inf), (None, 1)]
+    )
+    lp_copy = deepcopy(lp)
+
+    _clean_inputs(lp)
+
+    assert_allclose(lp.c, lp_copy.c, err_msg="c modified by _clean_inputs")
+    assert_allclose(lp.A_ub, lp_copy.A_ub, err_msg="A_ub modified by _clean_inputs")
+    assert_allclose(lp.b_ub, lp_copy.b_ub, err_msg="b_ub modified by _clean_inputs")
+    assert_allclose(lp.A_eq, lp_copy.A_eq, err_msg="A_eq modified by _clean_inputs")
+    assert_allclose(lp.b_eq, lp_copy.b_eq, err_msg="b_eq modified by _clean_inputs")
+    assert_(lp.bounds == lp_copy.bounds, "bounds modified by _clean_inputs")
+
+
+def test_missing_inputs():
+    c = [1, 2]
+    A_ub = np.array([[1, 1], [2, 2]])
+    b_ub = np.array([1, 1])
+    A_eq = np.array([[1, 1], [2, 2]])
+    b_eq = np.array([1, 1])
+
+    assert_raises(TypeError, _clean_inputs)
+    assert_raises(TypeError, _clean_inputs, _LPProblem(c=None))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_ub=A_ub))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_ub=A_ub, b_ub=None))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, b_ub=b_ub))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_ub=None, b_ub=b_ub))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_eq=A_eq))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_eq=A_eq, b_eq=None))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, b_eq=b_eq))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_eq=None, b_eq=b_eq))
+
+
+def test_too_many_dimensions():
+    cb = [1, 2, 3, 4]
+    A = np.random.rand(4, 4)
+    bad2D = [[1, 2], [3, 4]]
+    bad3D = np.random.rand(4, 4, 4)
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=bad2D, A_ub=A, b_ub=cb))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=cb, A_ub=bad3D, b_ub=cb))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=cb, A_ub=A, b_ub=bad2D))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=cb, A_eq=bad3D, b_eq=cb))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=cb, A_eq=A, b_eq=bad2D))
+
+
+def test_too_few_dimensions():
+    bad = np.random.rand(4, 4).ravel()
+    cb = np.random.rand(4)
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=cb, A_ub=bad, b_ub=cb))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=cb, A_eq=bad, b_eq=cb))
+
+
+def test_inconsistent_dimensions():
+    m = 2
+    n = 4
+    c = [1, 2, 3, 4]
+
+    Agood = np.random.rand(m, n)
+    Abad = np.random.rand(m, n + 1)
+    bgood = np.random.rand(m)
+    bbad = np.random.rand(m + 1)
+    boundsbad = [(0, 1)] * (n + 1)
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_ub=Abad, b_ub=bgood))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_ub=Agood, b_ub=bbad))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_eq=Abad, b_eq=bgood))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, A_eq=Agood, b_eq=bbad))
+    assert_raises(ValueError, _clean_inputs, _LPProblem(c=c, bounds=boundsbad))
+    with np.testing.suppress_warnings() as sup:
+        sup.filter(VisibleDeprecationWarning, "Creating an ndarray from ragged")
+        assert_raises(ValueError, _clean_inputs,
+                      _LPProblem(c=c, bounds=[[1, 2], [2, 3], [3, 4], [4, 5, 6]]))
+
+
+def test_type_errors():
+    lp = _LPProblem(
+        c=[1, 2],
+        A_ub=np.array([[1, 1], [2, 2]]),
+        b_ub=np.array([1, 1]),
+        A_eq=np.array([[1, 1], [2, 2]]),
+        b_eq=np.array([1, 1]),
+        bounds=[(0, 1)]
+    )
+    bad = "hello"
+
+    assert_raises(TypeError, _clean_inputs, lp._replace(c=bad))
+    assert_raises(TypeError, _clean_inputs, lp._replace(A_ub=bad))
+    assert_raises(TypeError, _clean_inputs, lp._replace(b_ub=bad))
+    assert_raises(TypeError, _clean_inputs, lp._replace(A_eq=bad))
+    assert_raises(TypeError, _clean_inputs, lp._replace(b_eq=bad))
+
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=bad))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds="hi"))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=["hi"]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=[("hi")]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=[(1, "")]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=[(1, 2), (1, "")]))
+    assert_raises(TypeError, _clean_inputs,
+                  lp._replace(bounds=[(1, date(2020, 2, 29))]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=[[[1, 2]]]))
+
+
+def test_non_finite_errors():
+    lp = _LPProblem(
+        c=[1, 2],
+        A_ub=np.array([[1, 1], [2, 2]]),
+        b_ub=np.array([1, 1]),
+        A_eq=np.array([[1, 1], [2, 2]]),
+        b_eq=np.array([1, 1]),
+        bounds=[(0, 1)]
+    )
+    assert_raises(ValueError, _clean_inputs, lp._replace(c=[0, None]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(c=[np.inf, 0]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(c=[0, -np.inf]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(c=[np.nan, 0]))
+
+    assert_raises(ValueError, _clean_inputs, lp._replace(A_ub=[[1, 2], [None, 1]]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(b_ub=[np.inf, 1]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(A_eq=[[1, 2], [1, -np.inf]]))
+    assert_raises(ValueError, _clean_inputs, lp._replace(b_eq=[1, np.nan]))
+
+
+def test__clean_inputs1():
+    lp = _LPProblem(
+        c=[1, 2],
+        A_ub=[[1, 1], [2, 2]],
+        b_ub=[1, 1],
+        A_eq=[[1, 1], [2, 2]],
+        b_eq=[1, 1],
+        bounds=None
+    )
+
+    lp_cleaned = _clean_inputs(lp)
+
+    assert_allclose(lp_cleaned.c, np.array(lp.c))
+    assert_allclose(lp_cleaned.A_ub, np.array(lp.A_ub))
+    assert_allclose(lp_cleaned.b_ub, np.array(lp.b_ub))
+    assert_allclose(lp_cleaned.A_eq, np.array(lp.A_eq))
+    assert_allclose(lp_cleaned.b_eq, np.array(lp.b_eq))
+    assert_equal(lp_cleaned.bounds, [(0, np.inf)] * 2)
+
+    assert_(lp_cleaned.c.shape == (2,), "")
+    assert_(lp_cleaned.A_ub.shape == (2, 2), "")
+    assert_(lp_cleaned.b_ub.shape == (2,), "")
+    assert_(lp_cleaned.A_eq.shape == (2, 2), "")
+    assert_(lp_cleaned.b_eq.shape == (2,), "")
+
+
+def test__clean_inputs2():
+    lp = _LPProblem(
+        c=1,
+        A_ub=[[1]],
+        b_ub=1,
+        A_eq=[[1]],
+        b_eq=1,
+        bounds=(0, 1)
+    )
+
+    lp_cleaned = _clean_inputs(lp)
+
+    assert_allclose(lp_cleaned.c, np.array(lp.c))
+    assert_allclose(lp_cleaned.A_ub, np.array(lp.A_ub))
+    assert_allclose(lp_cleaned.b_ub, np.array(lp.b_ub))
+    assert_allclose(lp_cleaned.A_eq, np.array(lp.A_eq))
+    assert_allclose(lp_cleaned.b_eq, np.array(lp.b_eq))
+    assert_equal(lp_cleaned.bounds, [(0, 1)])
+
+    assert_(lp_cleaned.c.shape == (1,), "")
+    assert_(lp_cleaned.A_ub.shape == (1, 1), "")
+    assert_(lp_cleaned.b_ub.shape == (1,), "")
+    assert_(lp_cleaned.A_eq.shape == (1, 1), "")
+    assert_(lp_cleaned.b_eq.shape == (1,), "")
+
+
+def test__clean_inputs3():
+    lp = _LPProblem(
+        c=[[1, 2]],
+        A_ub=np.random.rand(2, 2),
+        b_ub=[[1], [2]],
+        A_eq=np.random.rand(2, 2),
+        b_eq=[[1], [2]],
+        bounds=[(0, 1)]
+    )
+
+    lp_cleaned = _clean_inputs(lp)
+
+    assert_allclose(lp_cleaned.c, np.array([1, 2]))
+    assert_allclose(lp_cleaned.b_ub, np.array([1, 2]))
+    assert_allclose(lp_cleaned.b_eq, np.array([1, 2]))
+    assert_equal(lp_cleaned.bounds, [(0, 1)] * 2)
+
+    assert_(lp_cleaned.c.shape == (2,), "")
+    assert_(lp_cleaned.b_ub.shape == (2,), "")
+    assert_(lp_cleaned.b_eq.shape == (2,), "")
+
+
+def test_bad_bounds():
+    lp = _LPProblem(c=[1, 2])
+
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=(1, 2, 2)))
+    assert_raises(ValueError, _clean_inputs, lp._replace(bounds=[(1, 2, 2)]))
+    with np.testing.suppress_warnings() as sup:
+        sup.filter(VisibleDeprecationWarning, "Creating an ndarray from ragged")
+        assert_raises(ValueError, _clean_inputs,
+                      lp._replace(bounds=[(1, 2), (1, 2, 2)]))
+    assert_raises(ValueError, _clean_inputs,
+                  lp._replace(bounds=[(1, 2), (1, 2), (1, 2)]))
+
+    lp = _LPProblem(c=[1, 2, 3, 4])
+
+    assert_raises(ValueError, _clean_inputs,
+                  lp._replace(bounds=[(1, 2, 3, 4), (1, 2, 3, 4)]))
+
+
+def test_good_bounds():
+    lp = _LPProblem(c=[1, 2])
+
+    lp_cleaned = _clean_inputs(lp)  # lp.bounds is None by default
+    assert_equal(lp_cleaned.bounds, [(0, np.inf)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[]))
+    assert_equal(lp_cleaned.bounds, [(0, np.inf)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[[]]))
+    assert_equal(lp_cleaned.bounds, [(0, np.inf)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=(1, 2)))
+    assert_equal(lp_cleaned.bounds, [(1, 2)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(1, 2)]))
+    assert_equal(lp_cleaned.bounds, [(1, 2)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(1, None)]))
+    assert_equal(lp_cleaned.bounds, [(1, np.inf)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(None, 1)]))
+    assert_equal(lp_cleaned.bounds, [(-np.inf, 1)] * 2)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(None, None), (-np.inf, None)]))
+    assert_equal(lp_cleaned.bounds, [(-np.inf, np.inf)] * 2)
+
+    lp = _LPProblem(c=[1, 2, 3, 4])
+
+    lp_cleaned = _clean_inputs(lp)  # lp.bounds is None by default
+    assert_equal(lp_cleaned.bounds, [(0, np.inf)] * 4)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=(1, 2)))
+    assert_equal(lp_cleaned.bounds, [(1, 2)] * 4)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(1, 2)]))
+    assert_equal(lp_cleaned.bounds, [(1, 2)] * 4)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(1, None)]))
+    assert_equal(lp_cleaned.bounds, [(1, np.inf)] * 4)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(None, 1)]))
+    assert_equal(lp_cleaned.bounds, [(-np.inf, 1)] * 4)
+
+    lp_cleaned = _clean_inputs(lp._replace(bounds=[(None, None),
+                                                   (-np.inf, None),
+                                                   (None, np.inf),
+                                                   (-np.inf, np.inf)]))
+    assert_equal(lp_cleaned.bounds, [(-np.inf, np.inf)] * 4)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__numdiff.py

@@ -0,0 +1,815 @@
+import math
+from itertools import product
+
+import numpy as np
+from numpy.testing import assert_allclose, assert_equal, assert_
+from pytest import raises as assert_raises
+
+from scipy.sparse import csr_matrix, csc_matrix, lil_matrix
+
+from scipy.optimize._numdiff import (
+    _adjust_scheme_to_bounds, approx_derivative, check_derivative,
+    group_columns, _eps_for_method, _compute_absolute_step)
+
+
+def test_group_columns():
+    structure = [
+        [1, 1, 0, 0, 0, 0],
+        [1, 1, 1, 0, 0, 0],
+        [0, 1, 1, 1, 0, 0],
+        [0, 0, 1, 1, 1, 0],
+        [0, 0, 0, 1, 1, 1],
+        [0, 0, 0, 0, 1, 1],
+        [0, 0, 0, 0, 0, 0]
+    ]
+    for transform in [np.asarray, csr_matrix, csc_matrix, lil_matrix]:
+        A = transform(structure)
+        order = np.arange(6)
+        groups_true = np.array([0, 1, 2, 0, 1, 2])
+        groups = group_columns(A, order)
+        assert_equal(groups, groups_true)
+
+        order = [1, 2, 4, 3, 5, 0]
+        groups_true = np.array([2, 0, 1, 2, 0, 1])
+        groups = group_columns(A, order)
+        assert_equal(groups, groups_true)
+
+    # Test repeatability.
+    groups_1 = group_columns(A)
+    groups_2 = group_columns(A)
+    assert_equal(groups_1, groups_2)
+
+
+def test_correct_fp_eps():
+    # check that relative step size is correct for FP size
+    EPS = np.finfo(np.float64).eps
+    relative_step = {"2-point": EPS**0.5,
+                    "3-point": EPS**(1/3),
+                     "cs": EPS**0.5}
+    for method in ['2-point', '3-point', 'cs']:
+        assert_allclose(
+            _eps_for_method(np.float64, np.float64, method),
+            relative_step[method])
+        assert_allclose(
+            _eps_for_method(np.complex128, np.complex128, method),
+            relative_step[method]
+        )
+
+    # check another FP size
+    EPS = np.finfo(np.float32).eps
+    relative_step = {"2-point": EPS**0.5,
+                    "3-point": EPS**(1/3),
+                     "cs": EPS**0.5}
+
+    for method in ['2-point', '3-point', 'cs']:
+        assert_allclose(
+            _eps_for_method(np.float64, np.float32, method),
+            relative_step[method]
+        )
+        assert_allclose(
+            _eps_for_method(np.float32, np.float64, method),
+            relative_step[method]
+        )
+        assert_allclose(
+            _eps_for_method(np.float32, np.float32, method),
+            relative_step[method]
+        )
+
+
+class TestAdjustSchemeToBounds:
+    def test_no_bounds(self):
+        x0 = np.zeros(3)
+        h = np.full(3, 1e-2)
+        inf_lower = np.empty_like(x0)
+        inf_upper = np.empty_like(x0)
+        inf_lower.fill(-np.inf)
+        inf_upper.fill(np.inf)
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 1, '1-sided', inf_lower, inf_upper)
+        assert_allclose(h_adjusted, h)
+        assert_(np.all(one_sided))
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 2, '1-sided', inf_lower, inf_upper)
+        assert_allclose(h_adjusted, h)
+        assert_(np.all(one_sided))
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 1, '2-sided', inf_lower, inf_upper)
+        assert_allclose(h_adjusted, h)
+        assert_(np.all(~one_sided))
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 2, '2-sided', inf_lower, inf_upper)
+        assert_allclose(h_adjusted, h)
+        assert_(np.all(~one_sided))
+
+    def test_with_bound(self):
+        x0 = np.array([0.0, 0.85, -0.85])
+        lb = -np.ones(3)
+        ub = np.ones(3)
+        h = np.array([1, 1, -1]) * 1e-1
+
+        h_adjusted, _ = _adjust_scheme_to_bounds(x0, h, 1, '1-sided', lb, ub)
+        assert_allclose(h_adjusted, h)
+
+        h_adjusted, _ = _adjust_scheme_to_bounds(x0, h, 2, '1-sided', lb, ub)
+        assert_allclose(h_adjusted, np.array([1, -1, 1]) * 1e-1)
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 1, '2-sided', lb, ub)
+        assert_allclose(h_adjusted, np.abs(h))
+        assert_(np.all(~one_sided))
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 2, '2-sided', lb, ub)
+        assert_allclose(h_adjusted, np.array([1, -1, 1]) * 1e-1)
+        assert_equal(one_sided, np.array([False, True, True]))
+
+    def test_tight_bounds(self):
+        lb = np.array([-0.03, -0.03])
+        ub = np.array([0.05, 0.05])
+        x0 = np.array([0.0, 0.03])
+        h = np.array([-0.1, -0.1])
+
+        h_adjusted, _ = _adjust_scheme_to_bounds(x0, h, 1, '1-sided', lb, ub)
+        assert_allclose(h_adjusted, np.array([0.05, -0.06]))
+
+        h_adjusted, _ = _adjust_scheme_to_bounds(x0, h, 2, '1-sided', lb, ub)
+        assert_allclose(h_adjusted, np.array([0.025, -0.03]))
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 1, '2-sided', lb, ub)
+        assert_allclose(h_adjusted, np.array([0.03, -0.03]))
+        assert_equal(one_sided, np.array([False, True]))
+
+        h_adjusted, one_sided = _adjust_scheme_to_bounds(
+            x0, h, 2, '2-sided', lb, ub)
+        assert_allclose(h_adjusted, np.array([0.015, -0.015]))
+        assert_equal(one_sided, np.array([False, True]))
+
+
+class TestApproxDerivativesDense:
+    def fun_scalar_scalar(self, x):
+        return np.sinh(x)
+
+    def jac_scalar_scalar(self, x):
+        return np.cosh(x)
+
+    def fun_scalar_vector(self, x):
+        return np.array([x[0]**2, np.tan(x[0]), np.exp(x[0])])
+
+    def jac_scalar_vector(self, x):
+        return np.array(
+            [2 * x[0], np.cos(x[0]) ** -2, np.exp(x[0])]).reshape(-1, 1)
+
+    def fun_vector_scalar(self, x):
+        return np.sin(x[0] * x[1]) * np.log(x[0])
+
+    def wrong_dimensions_fun(self, x):
+        return np.array([x**2, np.tan(x), np.exp(x)])
+
+    def jac_vector_scalar(self, x):
+        return np.array([
+            x[1] * np.cos(x[0] * x[1]) * np.log(x[0]) +
+            np.sin(x[0] * x[1]) / x[0],
+            x[0] * np.cos(x[0] * x[1]) * np.log(x[0])
+        ])
+
+    def fun_vector_vector(self, x):
+        return np.array([
+            x[0] * np.sin(x[1]),
+            x[1] * np.cos(x[0]),
+            x[0] ** 3 * x[1] ** -0.5
+        ])
+
+    def jac_vector_vector(self, x):
+        return np.array([
+            [np.sin(x[1]), x[0] * np.cos(x[1])],
+            [-x[1] * np.sin(x[0]), np.cos(x[0])],
+            [3 * x[0] ** 2 * x[1] ** -0.5, -0.5 * x[0] ** 3 * x[1] ** -1.5]
+        ])
+
+    def fun_parametrized(self, x, c0, c1=1.0):
+        return np.array([np.exp(c0 * x[0]), np.exp(c1 * x[1])])
+
+    def jac_parametrized(self, x, c0, c1=0.1):
+        return np.array([
+            [c0 * np.exp(c0 * x[0]), 0],
+            [0, c1 * np.exp(c1 * x[1])]
+        ])
+
+    def fun_with_nan(self, x):
+        return x if np.abs(x) <= 1e-8 else np.nan
+
+    def jac_with_nan(self, x):
+        return 1.0 if np.abs(x) <= 1e-8 else np.nan
+
+    def fun_zero_jacobian(self, x):
+        return np.array([x[0] * x[1], np.cos(x[0] * x[1])])
+
+    def jac_zero_jacobian(self, x):
+        return np.array([
+            [x[1], x[0]],
+            [-x[1] * np.sin(x[0] * x[1]), -x[0] * np.sin(x[0] * x[1])]
+        ])
+
+    def jac_non_numpy(self, x):
+        # x can be a scalar or an array [val].
+        # Cast to true scalar before handing over to math.exp
+        xp = np.asarray(x).item()
+        return math.exp(xp)
+
+    def test_scalar_scalar(self):
+        x0 = 1.0
+        jac_diff_2 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       method='2-point')
+        jac_diff_3 = approx_derivative(self.fun_scalar_scalar, x0)
+        jac_diff_4 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       method='cs')
+        jac_true = self.jac_scalar_scalar(x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-9)
+        assert_allclose(jac_diff_4, jac_true, rtol=1e-12)
+
+    def test_scalar_scalar_abs_step(self):
+        # can approx_derivative use abs_step?
+        x0 = 1.0
+        jac_diff_2 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       method='2-point', abs_step=1.49e-8)
+        jac_diff_3 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       abs_step=1.49e-8)
+        jac_diff_4 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       method='cs', abs_step=1.49e-8)
+        jac_true = self.jac_scalar_scalar(x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-9)
+        assert_allclose(jac_diff_4, jac_true, rtol=1e-12)
+
+    def test_scalar_vector(self):
+        x0 = 0.5
+        jac_diff_2 = approx_derivative(self.fun_scalar_vector, x0,
+                                       method='2-point')
+        jac_diff_3 = approx_derivative(self.fun_scalar_vector, x0)
+        jac_diff_4 = approx_derivative(self.fun_scalar_vector, x0,
+                                       method='cs')
+        jac_true = self.jac_scalar_vector(np.atleast_1d(x0))
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-9)
+        assert_allclose(jac_diff_4, jac_true, rtol=1e-12)
+
+    def test_vector_scalar(self):
+        x0 = np.array([100.0, -0.5])
+        jac_diff_2 = approx_derivative(self.fun_vector_scalar, x0,
+                                       method='2-point')
+        jac_diff_3 = approx_derivative(self.fun_vector_scalar, x0)
+        jac_diff_4 = approx_derivative(self.fun_vector_scalar, x0,
+                                       method='cs')
+        jac_true = self.jac_vector_scalar(x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-7)
+        assert_allclose(jac_diff_4, jac_true, rtol=1e-12)
+
+    def test_vector_scalar_abs_step(self):
+        # can approx_derivative use abs_step?
+        x0 = np.array([100.0, -0.5])
+        jac_diff_2 = approx_derivative(self.fun_vector_scalar, x0,
+                                       method='2-point', abs_step=1.49e-8)
+        jac_diff_3 = approx_derivative(self.fun_vector_scalar, x0,
+                                       abs_step=1.49e-8, rel_step=np.inf)
+        jac_diff_4 = approx_derivative(self.fun_vector_scalar, x0,
+                                       method='cs', abs_step=1.49e-8)
+        jac_true = self.jac_vector_scalar(x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=3e-9)
+        assert_allclose(jac_diff_4, jac_true, rtol=1e-12)
+
+    def test_vector_vector(self):
+        x0 = np.array([-100.0, 0.2])
+        jac_diff_2 = approx_derivative(self.fun_vector_vector, x0,
+                                       method='2-point')
+        jac_diff_3 = approx_derivative(self.fun_vector_vector, x0)
+        jac_diff_4 = approx_derivative(self.fun_vector_vector, x0,
+                                       method='cs')
+        jac_true = self.jac_vector_vector(x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-5)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_4, jac_true, rtol=1e-12)
+
+    def test_wrong_dimensions(self):
+        x0 = 1.0
+        assert_raises(RuntimeError, approx_derivative,
+                      self.wrong_dimensions_fun, x0)
+        f0 = self.wrong_dimensions_fun(np.atleast_1d(x0))
+        assert_raises(ValueError, approx_derivative,
+                      self.wrong_dimensions_fun, x0, f0=f0)
+
+    def test_custom_rel_step(self):
+        x0 = np.array([-0.1, 0.1])
+        jac_diff_2 = approx_derivative(self.fun_vector_vector, x0,
+                                       method='2-point', rel_step=1e-4)
+        jac_diff_3 = approx_derivative(self.fun_vector_vector, x0,
+                                       rel_step=1e-4)
+        jac_true = self.jac_vector_vector(x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-2)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-4)
+
+    def test_options(self):
+        x0 = np.array([1.0, 1.0])
+        c0 = -1.0
+        c1 = 1.0
+        lb = 0.0
+        ub = 2.0
+        f0 = self.fun_parametrized(x0, c0, c1=c1)
+        rel_step = np.array([-1e-6, 1e-7])
+        jac_true = self.jac_parametrized(x0, c0, c1)
+        jac_diff_2 = approx_derivative(
+            self.fun_parametrized, x0, method='2-point', rel_step=rel_step,
+            f0=f0, args=(c0,), kwargs=dict(c1=c1), bounds=(lb, ub))
+        jac_diff_3 = approx_derivative(
+            self.fun_parametrized, x0, rel_step=rel_step,
+            f0=f0, args=(c0,), kwargs=dict(c1=c1), bounds=(lb, ub))
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-9)
+
+    def test_with_bounds_2_point(self):
+        lb = -np.ones(2)
+        ub = np.ones(2)
+
+        x0 = np.array([-2.0, 0.2])
+        assert_raises(ValueError, approx_derivative,
+                      self.fun_vector_vector, x0, bounds=(lb, ub))
+
+        x0 = np.array([-1.0, 1.0])
+        jac_diff = approx_derivative(self.fun_vector_vector, x0,
+                                     method='2-point', bounds=(lb, ub))
+        jac_true = self.jac_vector_vector(x0)
+        assert_allclose(jac_diff, jac_true, rtol=1e-6)
+
+    def test_with_bounds_3_point(self):
+        lb = np.array([1.0, 1.0])
+        ub = np.array([2.0, 2.0])
+
+        x0 = np.array([1.0, 2.0])
+        jac_true = self.jac_vector_vector(x0)
+
+        jac_diff = approx_derivative(self.fun_vector_vector, x0)
+        assert_allclose(jac_diff, jac_true, rtol=1e-9)
+
+        jac_diff = approx_derivative(self.fun_vector_vector, x0,
+                                     bounds=(lb, np.inf))
+        assert_allclose(jac_diff, jac_true, rtol=1e-9)
+
+        jac_diff = approx_derivative(self.fun_vector_vector, x0,
+                                     bounds=(-np.inf, ub))
+        assert_allclose(jac_diff, jac_true, rtol=1e-9)
+
+        jac_diff = approx_derivative(self.fun_vector_vector, x0,
+                                     bounds=(lb, ub))
+        assert_allclose(jac_diff, jac_true, rtol=1e-9)
+
+    def test_tight_bounds(self):
+        x0 = np.array([10.0, 10.0])
+        lb = x0 - 3e-9
+        ub = x0 + 2e-9
+        jac_true = self.jac_vector_vector(x0)
+        jac_diff = approx_derivative(
+            self.fun_vector_vector, x0, method='2-point', bounds=(lb, ub))
+        assert_allclose(jac_diff, jac_true, rtol=1e-6)
+        jac_diff = approx_derivative(
+            self.fun_vector_vector, x0, method='2-point',
+            rel_step=1e-6, bounds=(lb, ub))
+        assert_allclose(jac_diff, jac_true, rtol=1e-6)
+
+        jac_diff = approx_derivative(
+            self.fun_vector_vector, x0, bounds=(lb, ub))
+        assert_allclose(jac_diff, jac_true, rtol=1e-6)
+        jac_diff = approx_derivative(
+            self.fun_vector_vector, x0, rel_step=1e-6, bounds=(lb, ub))
+        assert_allclose(jac_true, jac_diff, rtol=1e-6)
+
+    def test_bound_switches(self):
+        lb = -1e-8
+        ub = 1e-8
+        x0 = 0.0
+        jac_true = self.jac_with_nan(x0)
+        jac_diff_2 = approx_derivative(
+            self.fun_with_nan, x0, method='2-point', rel_step=1e-6,
+            bounds=(lb, ub))
+        jac_diff_3 = approx_derivative(
+            self.fun_with_nan, x0, rel_step=1e-6, bounds=(lb, ub))
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-9)
+
+        x0 = 1e-8
+        jac_true = self.jac_with_nan(x0)
+        jac_diff_2 = approx_derivative(
+            self.fun_with_nan, x0, method='2-point', rel_step=1e-6,
+            bounds=(lb, ub))
+        jac_diff_3 = approx_derivative(
+            self.fun_with_nan, x0, rel_step=1e-6, bounds=(lb, ub))
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-9)
+
+    def test_non_numpy(self):
+        x0 = 1.0
+        jac_true = self.jac_non_numpy(x0)
+        jac_diff_2 = approx_derivative(self.jac_non_numpy, x0,
+                                       method='2-point')
+        jac_diff_3 = approx_derivative(self.jac_non_numpy, x0)
+        assert_allclose(jac_diff_2, jac_true, rtol=1e-6)
+        assert_allclose(jac_diff_3, jac_true, rtol=1e-8)
+
+        # math.exp cannot handle complex arguments, hence this raises
+        assert_raises(TypeError, approx_derivative, self.jac_non_numpy, x0,
+                      **dict(method='cs'))
+
+    def test_fp(self):
+        # checks that approx_derivative works for FP size other than 64.
+        # Example is derived from the minimal working example in gh12991.
+        np.random.seed(1)
+
+        def func(p, x):
+            return p[0] + p[1] * x
+
+        def err(p, x, y):
+            return func(p, x) - y
+
+        x = np.linspace(0, 1, 100, dtype=np.float64)
+        y = np.random.random(100).astype(np.float64)
+        p0 = np.array([-1.0, -1.0])
+
+        jac_fp64 = approx_derivative(err, p0, method='2-point', args=(x, y))
+
+        # parameter vector is float32, func output is float64
+        jac_fp = approx_derivative(err, p0.astype(np.float32),
+                                   method='2-point', args=(x, y))
+        assert err(p0, x, y).dtype == np.float64
+        assert_allclose(jac_fp, jac_fp64, atol=1e-3)
+
+        # parameter vector is float64, func output is float32
+        def err_fp32(p):
+            assert p.dtype == np.float32
+            return err(p, x, y).astype(np.float32)
+
+        jac_fp = approx_derivative(err_fp32, p0.astype(np.float32),
+                                   method='2-point')
+        assert_allclose(jac_fp, jac_fp64, atol=1e-3)
+
+        # check upper bound of error on the derivative for 2-point
+        def f(x):
+            return np.sin(x)
+        def g(x):
+            return np.cos(x)
+        def hess(x):
+            return -np.sin(x)
+
+        def calc_atol(h, x0, f, hess, EPS):
+            # truncation error
+            t0 = h / 2 * max(np.abs(hess(x0)), np.abs(hess(x0 + h)))
+            # roundoff error. There may be a divisor (>1) missing from
+            # the following line, so this contribution is possibly
+            # overestimated
+            t1 = EPS / h * max(np.abs(f(x0)), np.abs(f(x0 + h)))
+            return t0 + t1
+
+        for dtype in [np.float16, np.float32, np.float64]:
+            EPS = np.finfo(dtype).eps
+            x0 = np.array(1.0).astype(dtype)
+            h = _compute_absolute_step(None, x0, f(x0), '2-point')
+            atol = calc_atol(h, x0, f, hess, EPS)
+            err = approx_derivative(f, x0, method='2-point',
+                                    abs_step=h) - g(x0)
+            assert abs(err) < atol
+
+    def test_check_derivative(self):
+        x0 = np.array([-10.0, 10])
+        accuracy = check_derivative(self.fun_vector_vector,
+                                    self.jac_vector_vector, x0)
+        assert_(accuracy < 1e-9)
+        accuracy = check_derivative(self.fun_vector_vector,
+                                    self.jac_vector_vector, x0)
+        assert_(accuracy < 1e-6)
+
+        x0 = np.array([0.0, 0.0])
+        accuracy = check_derivative(self.fun_zero_jacobian,
+                                    self.jac_zero_jacobian, x0)
+        assert_(accuracy == 0)
+        accuracy = check_derivative(self.fun_zero_jacobian,
+                                    self.jac_zero_jacobian, x0)
+        assert_(accuracy == 0)
+
+
+class TestApproxDerivativeSparse:
+    # Example from Numerical Optimization 2nd edition, p. 198.
+    def setup_method(self):
+        np.random.seed(0)
+        self.n = 50
+        self.lb = -0.1 * (1 + np.arange(self.n))
+        self.ub = 0.1 * (1 + np.arange(self.n))
+        self.x0 = np.empty(self.n)
+        self.x0[::2] = (1 - 1e-7) * self.lb[::2]
+        self.x0[1::2] = (1 - 1e-7) * self.ub[1::2]
+
+        self.J_true = self.jac(self.x0)
+
+    def fun(self, x):
+        e = x[1:]**3 - x[:-1]**2
+        return np.hstack((0, 3 * e)) + np.hstack((2 * e, 0))
+
+    def jac(self, x):
+        n = x.size
+        J = np.zeros((n, n))
+        J[0, 0] = -4 * x[0]
+        J[0, 1] = 6 * x[1]**2
+        for i in range(1, n - 1):
+            J[i, i - 1] = -6 * x[i-1]
+            J[i, i] = 9 * x[i]**2 - 4 * x[i]
+            J[i, i + 1] = 6 * x[i+1]**2
+        J[-1, -1] = 9 * x[-1]**2
+        J[-1, -2] = -6 * x[-2]
+
+        return J
+
+    def structure(self, n):
+        A = np.zeros((n, n), dtype=int)
+        A[0, 0] = 1
+        A[0, 1] = 1
+        for i in range(1, n - 1):
+            A[i, i - 1: i + 2] = 1
+        A[-1, -1] = 1
+        A[-1, -2] = 1
+
+        return A
+
+    def test_all(self):
+        A = self.structure(self.n)
+        order = np.arange(self.n)
+        groups_1 = group_columns(A, order)
+        np.random.shuffle(order)
+        groups_2 = group_columns(A, order)
+
+        for method, groups, l, u in product(
+                ['2-point', '3-point', 'cs'], [groups_1, groups_2],
+                [-np.inf, self.lb], [np.inf, self.ub]):
+            J = approx_derivative(self.fun, self.x0, method=method,
+                                  bounds=(l, u), sparsity=(A, groups))
+            assert_(isinstance(J, csr_matrix))
+            assert_allclose(J.toarray(), self.J_true, rtol=1e-6)
+
+            rel_step = np.full_like(self.x0, 1e-8)
+            rel_step[::2] *= -1
+            J = approx_derivative(self.fun, self.x0, method=method,
+                                  rel_step=rel_step, sparsity=(A, groups))
+            assert_allclose(J.toarray(), self.J_true, rtol=1e-5)
+
+    def test_no_precomputed_groups(self):
+        A = self.structure(self.n)
+        J = approx_derivative(self.fun, self.x0, sparsity=A)
+        assert_allclose(J.toarray(), self.J_true, rtol=1e-6)
+
+    def test_equivalence(self):
+        structure = np.ones((self.n, self.n), dtype=int)
+        groups = np.arange(self.n)
+        for method in ['2-point', '3-point', 'cs']:
+            J_dense = approx_derivative(self.fun, self.x0, method=method)
+            J_sparse = approx_derivative(
+                self.fun, self.x0, sparsity=(structure, groups), method=method)
+            assert_allclose(J_dense, J_sparse.toarray(),
+                            rtol=5e-16, atol=7e-15)
+
+    def test_check_derivative(self):
+        def jac(x):
+            return csr_matrix(self.jac(x))
+
+        accuracy = check_derivative(self.fun, jac, self.x0,
+                                    bounds=(self.lb, self.ub))
+        assert_(accuracy < 1e-9)
+
+        accuracy = check_derivative(self.fun, jac, self.x0,
+                                    bounds=(self.lb, self.ub))
+        assert_(accuracy < 1e-9)
+
+
+class TestApproxDerivativeLinearOperator:
+
+    def fun_scalar_scalar(self, x):
+        return np.sinh(x)
+
+    def jac_scalar_scalar(self, x):
+        return np.cosh(x)
+
+    def fun_scalar_vector(self, x):
+        return np.array([x[0]**2, np.tan(x[0]), np.exp(x[0])])
+
+    def jac_scalar_vector(self, x):
+        return np.array(
+            [2 * x[0], np.cos(x[0]) ** -2, np.exp(x[0])]).reshape(-1, 1)
+
+    def fun_vector_scalar(self, x):
+        return np.sin(x[0] * x[1]) * np.log(x[0])
+
+    def jac_vector_scalar(self, x):
+        return np.array([
+            x[1] * np.cos(x[0] * x[1]) * np.log(x[0]) +
+            np.sin(x[0] * x[1]) / x[0],
+            x[0] * np.cos(x[0] * x[1]) * np.log(x[0])
+        ])
+
+    def fun_vector_vector(self, x):
+        return np.array([
+            x[0] * np.sin(x[1]),
+            x[1] * np.cos(x[0]),
+            x[0] ** 3 * x[1] ** -0.5
+        ])
+
+    def jac_vector_vector(self, x):
+        return np.array([
+            [np.sin(x[1]), x[0] * np.cos(x[1])],
+            [-x[1] * np.sin(x[0]), np.cos(x[0])],
+            [3 * x[0] ** 2 * x[1] ** -0.5, -0.5 * x[0] ** 3 * x[1] ** -1.5]
+        ])
+
+    def test_scalar_scalar(self):
+        x0 = 1.0
+        jac_diff_2 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       method='2-point',
+                                       as_linear_operator=True)
+        jac_diff_3 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       as_linear_operator=True)
+        jac_diff_4 = approx_derivative(self.fun_scalar_scalar, x0,
+                                       method='cs',
+                                       as_linear_operator=True)
+        jac_true = self.jac_scalar_scalar(x0)
+        np.random.seed(1)
+        for i in range(10):
+            p = np.random.uniform(-10, 10, size=(1,))
+            assert_allclose(jac_diff_2.dot(p), jac_true*p,
+                            rtol=1e-5)
+            assert_allclose(jac_diff_3.dot(p), jac_true*p,
+                            rtol=5e-6)
+            assert_allclose(jac_diff_4.dot(p), jac_true*p,
+                            rtol=5e-6)
+
+    def test_scalar_vector(self):
+        x0 = 0.5
+        jac_diff_2 = approx_derivative(self.fun_scalar_vector, x0,
+                                       method='2-point',
+                                       as_linear_operator=True)
+        jac_diff_3 = approx_derivative(self.fun_scalar_vector, x0,
+                                       as_linear_operator=True)
+        jac_diff_4 = approx_derivative(self.fun_scalar_vector, x0,
+                                       method='cs',
+                                       as_linear_operator=True)
+        jac_true = self.jac_scalar_vector(np.atleast_1d(x0))
+        np.random.seed(1)
+        for i in range(10):
+            p = np.random.uniform(-10, 10, size=(1,))
+            assert_allclose(jac_diff_2.dot(p), jac_true.dot(p),
+                            rtol=1e-5)
+            assert_allclose(jac_diff_3.dot(p), jac_true.dot(p),
+                            rtol=5e-6)
+            assert_allclose(jac_diff_4.dot(p), jac_true.dot(p),
+                            rtol=5e-6)
+
+    def test_vector_scalar(self):
+        x0 = np.array([100.0, -0.5])
+        jac_diff_2 = approx_derivative(self.fun_vector_scalar, x0,
+                                       method='2-point',
+                                       as_linear_operator=True)
+        jac_diff_3 = approx_derivative(self.fun_vector_scalar, x0,
+                                       as_linear_operator=True)
+        jac_diff_4 = approx_derivative(self.fun_vector_scalar, x0,
+                                       method='cs',
+                                       as_linear_operator=True)
+        jac_true = self.jac_vector_scalar(x0)
+        np.random.seed(1)
+        for i in range(10):
+            p = np.random.uniform(-10, 10, size=x0.shape)
+            assert_allclose(jac_diff_2.dot(p), np.atleast_1d(jac_true.dot(p)),
+                            rtol=1e-5)
+            assert_allclose(jac_diff_3.dot(p), np.atleast_1d(jac_true.dot(p)),
+                            rtol=5e-6)
+            assert_allclose(jac_diff_4.dot(p), np.atleast_1d(jac_true.dot(p)),
+                            rtol=1e-7)
+
+    def test_vector_vector(self):
+        x0 = np.array([-100.0, 0.2])
+        jac_diff_2 = approx_derivative(self.fun_vector_vector, x0,
+                                       method='2-point',
+                                       as_linear_operator=True)
+        jac_diff_3 = approx_derivative(self.fun_vector_vector, x0,
+                                       as_linear_operator=True)
+        jac_diff_4 = approx_derivative(self.fun_vector_vector, x0,
+                                       method='cs',
+                                       as_linear_operator=True)
+        jac_true = self.jac_vector_vector(x0)
+        np.random.seed(1)
+        for i in range(10):
+            p = np.random.uniform(-10, 10, size=x0.shape)
+            assert_allclose(jac_diff_2.dot(p), jac_true.dot(p), rtol=1e-5)
+            assert_allclose(jac_diff_3.dot(p), jac_true.dot(p), rtol=1e-6)
+            assert_allclose(jac_diff_4.dot(p), jac_true.dot(p), rtol=1e-7)
+
+    def test_exception(self):
+        x0 = np.array([-100.0, 0.2])
+        assert_raises(ValueError, approx_derivative,
+                      self.fun_vector_vector, x0,
+                      method='2-point', bounds=(1, np.inf))
+
+
+def test_absolute_step_sign():
+    # test for gh12487
+    # if an absolute step is specified for 2-point differences make sure that
+    # the side corresponds to the step. i.e. if step is positive then forward
+    # differences should be used, if step is negative then backwards
+    # differences should be used.
+
+    # function has double discontinuity at x = [-1, -1]
+    # first component is \/, second component is /\
+    def f(x):
+        return -np.abs(x[0] + 1) + np.abs(x[1] + 1)
+
+    # check that the forward difference is used
+    grad = approx_derivative(f, [-1, -1], method='2-point', abs_step=1e-8)
+    assert_allclose(grad, [-1.0, 1.0])
+
+    # check that the backwards difference is used
+    grad = approx_derivative(f, [-1, -1], method='2-point', abs_step=-1e-8)
+    assert_allclose(grad, [1.0, -1.0])
+
+    # check that the forwards difference is used with a step for both
+    # parameters
+    grad = approx_derivative(
+        f, [-1, -1], method='2-point', abs_step=[1e-8, 1e-8]
+    )
+    assert_allclose(grad, [-1.0, 1.0])
+
+    # check that we can mix forward/backwards steps.
+    grad = approx_derivative(
+        f, [-1, -1], method='2-point', abs_step=[1e-8, -1e-8]
+     )
+    assert_allclose(grad, [-1.0, -1.0])
+    grad = approx_derivative(
+        f, [-1, -1], method='2-point', abs_step=[-1e-8, 1e-8]
+    )
+    assert_allclose(grad, [1.0, 1.0])
+
+    # the forward step should reverse to a backwards step if it runs into a
+    # bound
+    # This is kind of tested in TestAdjustSchemeToBounds, but only for a lower level
+    # function.
+    grad = approx_derivative(
+        f, [-1, -1], method='2-point', abs_step=1e-8,
+        bounds=(-np.inf, -1)
+    )
+    assert_allclose(grad, [1.0, -1.0])
+
+    grad = approx_derivative(
+        f, [-1, -1], method='2-point', abs_step=-1e-8, bounds=(-1, np.inf)
+    )
+    assert_allclose(grad, [-1.0, 1.0])
+
+
+def test__compute_absolute_step():
+    # tests calculation of absolute step from rel_step
+    methods = ['2-point', '3-point', 'cs']
+
+    x0 = np.array([1e-5, 0, 1, 1e5])
+
+    EPS = np.finfo(np.float64).eps
+    relative_step = {
+        "2-point": EPS**0.5,
+        "3-point": EPS**(1/3),
+        "cs": EPS**0.5
+    }
+    f0 = np.array(1.0)
+
+    for method in methods:
+        rel_step = relative_step[method]
+        correct_step = np.array([rel_step,
+                                 rel_step * 1.,
+                                 rel_step * 1.,
+                                 rel_step * np.abs(x0[3])])
+
+        abs_step = _compute_absolute_step(None, x0, f0, method)
+        assert_allclose(abs_step, correct_step)
+
+        sign_x0 = (-x0 >= 0).astype(float) * 2 - 1
+        abs_step = _compute_absolute_step(None, -x0, f0, method)
+        assert_allclose(abs_step, sign_x0 * correct_step)
+
+    # if a relative step is provided it should be used
+    rel_step = np.array([0.1, 1, 10, 100])
+    correct_step = np.array([rel_step[0] * x0[0],
+                             relative_step['2-point'],
+                             rel_step[2] * 1.,
+                             rel_step[3] * np.abs(x0[3])])
+
+    abs_step = _compute_absolute_step(rel_step, x0, f0, '2-point')
+    assert_allclose(abs_step, correct_step)
+
+    sign_x0 = (-x0 >= 0).astype(float) * 2 - 1
+    abs_step = _compute_absolute_step(rel_step, -x0, f0, '2-point')
+    assert_allclose(abs_step, sign_x0 * correct_step)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__remove_redundancy.py

@@ -0,0 +1,228 @@
+"""
+Unit test for Linear Programming via Simplex Algorithm.
+"""
+
+# TODO: add tests for:
+# https://github.com/scipy/scipy/issues/5400
+# https://github.com/scipy/scipy/issues/6690
+
+import numpy as np
+from numpy.testing import (
+    assert_,
+    assert_allclose,
+    assert_equal)
+
+from .test_linprog import magic_square
+from scipy.optimize._remove_redundancy import _remove_redundancy_svd
+from scipy.optimize._remove_redundancy import _remove_redundancy_pivot_dense
+from scipy.optimize._remove_redundancy import _remove_redundancy_pivot_sparse
+from scipy.optimize._remove_redundancy import _remove_redundancy_id
+
+from scipy.sparse import csc_matrix
+
+
+def setup_module():
+    np.random.seed(2017)
+
+
+def redundancy_removed(A, B):
+    """Checks whether a matrix contains only independent rows of another"""
+    for rowA in A:
+        # `rowA in B` is not a reliable check
+        for rowB in B:
+            if np.all(rowA == rowB):
+                break
+        else:
+            return False
+    return A.shape[0] == np.linalg.matrix_rank(A) == np.linalg.matrix_rank(B)
+
+
+class RRCommonTests:
+    def test_no_redundancy(self):
+        m, n = 10, 10
+        A0 = np.random.rand(m, n)
+        b0 = np.random.rand(m)
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_allclose(A0, A1)
+        assert_allclose(b0, b1)
+        assert_equal(status, 0)
+
+    def test_infeasible_zero_row(self):
+        A = np.eye(3)
+        A[1, :] = 0
+        b = np.random.rand(3)
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 2)
+
+    def test_remove_zero_row(self):
+        A = np.eye(3)
+        A[1, :] = 0
+        b = np.random.rand(3)
+        b[1] = 0
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 0)
+        assert_allclose(A1, A[[0, 2], :])
+        assert_allclose(b1, b[[0, 2]])
+
+    def test_infeasible_m_gt_n(self):
+        m, n = 20, 10
+        A0 = np.random.rand(m, n)
+        b0 = np.random.rand(m)
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_equal(status, 2)
+
+    def test_infeasible_m_eq_n(self):
+        m, n = 10, 10
+        A0 = np.random.rand(m, n)
+        b0 = np.random.rand(m)
+        A0[-1, :] = 2 * A0[-2, :]
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_equal(status, 2)
+
+    def test_infeasible_m_lt_n(self):
+        m, n = 9, 10
+        A0 = np.random.rand(m, n)
+        b0 = np.random.rand(m)
+        A0[-1, :] = np.arange(m - 1).dot(A0[:-1])
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_equal(status, 2)
+
+    def test_m_gt_n(self):
+        np.random.seed(2032)
+        m, n = 20, 10
+        A0 = np.random.rand(m, n)
+        b0 = np.random.rand(m)
+        x = np.linalg.solve(A0[:n, :], b0[:n])
+        b0[n:] = A0[n:, :].dot(x)
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], n)
+        assert_equal(np.linalg.matrix_rank(A1), n)
+
+    def test_m_gt_n_rank_deficient(self):
+        m, n = 20, 10
+        A0 = np.zeros((m, n))
+        A0[:, 0] = 1
+        b0 = np.ones(m)
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_equal(status, 0)
+        assert_allclose(A1, A0[0:1, :])
+        assert_allclose(b1, b0[0])
+
+    def test_m_lt_n_rank_deficient(self):
+        m, n = 9, 10
+        A0 = np.random.rand(m, n)
+        b0 = np.random.rand(m)
+        A0[-1, :] = np.arange(m - 1).dot(A0[:-1])
+        b0[-1] = np.arange(m - 1).dot(b0[:-1])
+        A1, b1, status, message = self.rr(A0, b0)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], 8)
+        assert_equal(np.linalg.matrix_rank(A1), 8)
+
+    def test_dense1(self):
+        A = np.ones((6, 6))
+        A[0, :3] = 0
+        A[1, 3:] = 0
+        A[3:, ::2] = -1
+        A[3, :2] = 0
+        A[4, 2:] = 0
+        b = np.zeros(A.shape[0])
+
+        A1, b1, status, message = self.rr(A, b)
+        assert_(redundancy_removed(A1, A))
+        assert_equal(status, 0)
+
+    def test_dense2(self):
+        A = np.eye(6)
+        A[-2, -1] = 1
+        A[-1, :] = 1
+        b = np.zeros(A.shape[0])
+        A1, b1, status, message = self.rr(A, b)
+        assert_(redundancy_removed(A1, A))
+        assert_equal(status, 0)
+
+    def test_dense3(self):
+        A = np.eye(6)
+        A[-2, -1] = 1
+        A[-1, :] = 1
+        b = np.random.rand(A.shape[0])
+        b[-1] = np.sum(b[:-1])
+        A1, b1, status, message = self.rr(A, b)
+        assert_(redundancy_removed(A1, A))
+        assert_equal(status, 0)
+
+    def test_m_gt_n_sparse(self):
+        np.random.seed(2013)
+        m, n = 20, 5
+        p = 0.1
+        A = np.random.rand(m, n)
+        A[np.random.rand(m, n) > p] = 0
+        rank = np.linalg.matrix_rank(A)
+        b = np.zeros(A.shape[0])
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], rank)
+        assert_equal(np.linalg.matrix_rank(A1), rank)
+
+    def test_m_lt_n_sparse(self):
+        np.random.seed(2017)
+        m, n = 20, 50
+        p = 0.05
+        A = np.random.rand(m, n)
+        A[np.random.rand(m, n) > p] = 0
+        rank = np.linalg.matrix_rank(A)
+        b = np.zeros(A.shape[0])
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], rank)
+        assert_equal(np.linalg.matrix_rank(A1), rank)
+
+    def test_m_eq_n_sparse(self):
+        np.random.seed(2017)
+        m, n = 100, 100
+        p = 0.01
+        A = np.random.rand(m, n)
+        A[np.random.rand(m, n) > p] = 0
+        rank = np.linalg.matrix_rank(A)
+        b = np.zeros(A.shape[0])
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], rank)
+        assert_equal(np.linalg.matrix_rank(A1), rank)
+
+    def test_magic_square(self):
+        A, b, c, numbers, _ = magic_square(3)
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], 23)
+        assert_equal(np.linalg.matrix_rank(A1), 23)
+
+    def test_magic_square2(self):
+        A, b, c, numbers, _ = magic_square(4)
+        A1, b1, status, message = self.rr(A, b)
+        assert_equal(status, 0)
+        assert_equal(A1.shape[0], 39)
+        assert_equal(np.linalg.matrix_rank(A1), 39)
+
+
+class TestRRSVD(RRCommonTests):
+    def rr(self, A, b):
+        return _remove_redundancy_svd(A, b)
+
+
+class TestRRPivotDense(RRCommonTests):
+    def rr(self, A, b):
+        return _remove_redundancy_pivot_dense(A, b)
+
+
+class TestRRID(RRCommonTests):
+    def rr(self, A, b):
+        return _remove_redundancy_id(A, b)
+
+
+class TestRRPivotSparse(RRCommonTests):
+    def rr(self, A, b):
+        rr_res = _remove_redundancy_pivot_sparse(csc_matrix(A), b)
+        A1, b1, status, message = rr_res
+        return A1.toarray(), b1, status, message

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__root.py

@@ -0,0 +1,123 @@
+"""
+Unit tests for optimization routines from _root.py.
+"""
+from numpy.testing import assert_, assert_equal
+import pytest
+from pytest import raises as assert_raises, warns as assert_warns
+import numpy as np
+
+from scipy.optimize import root
+
+
+class TestRoot:
+    def test_tol_parameter(self):
+        # Check that the minimize() tol= argument does something
+        def func(z):
+            x, y = z
+            return np.array([x**3 - 1, y**3 - 1])
+
+        def dfunc(z):
+            x, y = z
+            return np.array([[3*x**2, 0], [0, 3*y**2]])
+
+        for method in ['hybr', 'lm', 'broyden1', 'broyden2', 'anderson',
+                       'diagbroyden', 'krylov']:
+            if method in ('linearmixing', 'excitingmixing'):
+                # doesn't converge
+                continue
+
+            if method in ('hybr', 'lm'):
+                jac = dfunc
+            else:
+                jac = None
+
+            sol1 = root(func, [1.1,1.1], jac=jac, tol=1e-4, method=method)
+            sol2 = root(func, [1.1,1.1], jac=jac, tol=0.5, method=method)
+            msg = f"{method}: {func(sol1.x)} vs. {func(sol2.x)}"
+            assert_(sol1.success, msg)
+            assert_(sol2.success, msg)
+            assert_(abs(func(sol1.x)).max() < abs(func(sol2.x)).max(),
+                    msg)
+
+    def test_tol_norm(self):
+
+        def norm(x):
+            return abs(x[0])
+
+        for method in ['excitingmixing',
+                       'diagbroyden',
+                       'linearmixing',
+                       'anderson',
+                       'broyden1',
+                       'broyden2',
+                       'krylov']:
+
+            root(np.zeros_like, np.zeros(2), method=method,
+                options={"tol_norm": norm})
+
+    def test_minimize_scalar_coerce_args_param(self):
+        # github issue #3503
+        def func(z, f=1):
+            x, y = z
+            return np.array([x**3 - 1, y**3 - f])
+        root(func, [1.1, 1.1], args=1.5)
+
+    def test_f_size(self):
+        # gh8320
+        # check that decreasing the size of the returned array raises an error
+        # and doesn't segfault
+        class fun:
+            def __init__(self):
+                self.count = 0
+
+            def __call__(self, x):
+                self.count += 1
+
+                if not (self.count % 5):
+                    ret = x[0] + 0.5 * (x[0] - x[1]) ** 3 - 1.0
+                else:
+                    ret = ([x[0] + 0.5 * (x[0] - x[1]) ** 3 - 1.0,
+                           0.5 * (x[1] - x[0]) ** 3 + x[1]])
+
+                return ret
+
+        F = fun()
+        with assert_raises(ValueError):
+            root(F, [0.1, 0.0], method='lm')
+
+    def test_gh_10370(self):
+        # gh-10370 reported that passing both `args` and `jac` to `root` with
+        # `method='krylov'` caused a failure. Ensure that this is fixed whether
+        # the gradient is passed via `jac` or as a second output of `fun`.
+        def fun(x, ignored):
+            return [3*x[0] - 0.25*x[1]**2 + 10, 0.1*x[0]**2 + 5*x[1] - 2]
+
+        def grad(x, ignored):
+            return [[3, 0.5 * x[1]], [0.2 * x[0], 5]]
+
+        def fun_grad(x, ignored):
+            return fun(x, ignored), grad(x, ignored)
+
+        x0 = np.zeros(2)
+
+        ref = root(fun, x0, args=(1,), method='krylov')
+        message = 'Method krylov does not use the jacobian'
+        with assert_warns(RuntimeWarning, match=message):
+            res1 = root(fun, x0, args=(1,), method='krylov', jac=grad)
+        with assert_warns(RuntimeWarning, match=message):
+            res2 = root(fun_grad, x0, args=(1,), method='krylov', jac=True)
+
+        assert_equal(res1.x, ref.x)
+        assert_equal(res2.x, ref.x)
+        assert res1.success is res2.success is ref.success is True
+    
+    @pytest.mark.parametrize("method", ["hybr", "lm", "broyden1", "broyden2",
+                                        "anderson", "linearmixing",
+                                        "diagbroyden", "excitingmixing",
+                                        "krylov", "df-sane"])
+    def test_method_in_result(self, method):
+        def func(x):
+            return x - 1
+        
+        res = root(func, x0=[1], method=method)
+        assert res.method == method

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__shgo.py

@@ -0,0 +1,1159 @@
+import logging
+import sys
+
+import numpy
+import numpy as np
+import time
+from multiprocessing import Pool
+from numpy.testing import assert_allclose, IS_PYPY
+import pytest
+from pytest import raises as assert_raises, warns
+from scipy.optimize import (shgo, Bounds, minimize_scalar, minimize, rosen,
+                            rosen_der, rosen_hess, NonlinearConstraint)
+from scipy.optimize._constraints import new_constraint_to_old
+from scipy.optimize._shgo import SHGO
+
+
+class StructTestFunction:
+    def __init__(self, bounds, expected_x, expected_fun=None,
+                 expected_xl=None, expected_funl=None):
+        self.bounds = bounds
+        self.expected_x = expected_x
+        self.expected_fun = expected_fun
+        self.expected_xl = expected_xl
+        self.expected_funl = expected_funl
+
+
+def wrap_constraints(g):
+    cons = []
+    if g is not None:
+        if not isinstance(g, (tuple, list)):
+            g = (g,)
+        else:
+            pass
+        for g in g:
+            cons.append({'type': 'ineq',
+                         'fun': g})
+        cons = tuple(cons)
+    else:
+        cons = None
+    return cons
+
+
+class StructTest1(StructTestFunction):
+    def f(self, x):
+        return x[0] ** 2 + x[1] ** 2
+
+    def g(x):
+        return -(numpy.sum(x, axis=0) - 6.0)
+
+    cons = wrap_constraints(g)
+
+
+test1_1 = StructTest1(bounds=[(-1, 6), (-1, 6)],
+                      expected_x=[0, 0])
+test1_2 = StructTest1(bounds=[(0, 1), (0, 1)],
+                      expected_x=[0, 0])
+test1_3 = StructTest1(bounds=[(None, None), (None, None)],
+                      expected_x=[0, 0])
+
+
+class StructTest2(StructTestFunction):
+    """
+    Scalar function with several minima to test all minimiser retrievals
+    """
+
+    def f(self, x):
+        return (x - 30) * numpy.sin(x)
+
+    def g(x):
+        return 58 - numpy.sum(x, axis=0)
+
+    cons = wrap_constraints(g)
+
+
+test2_1 = StructTest2(bounds=[(0, 60)],
+                      expected_x=[1.53567906],
+                      expected_fun=-28.44677132,
+                      # Important: test that funl return is in the correct
+                      # order
+                      expected_xl=numpy.array([[1.53567906],
+                                               [55.01782167],
+                                               [7.80894889],
+                                               [48.74797493],
+                                               [14.07445705],
+                                               [42.4913859],
+                                               [20.31743841],
+                                               [36.28607535],
+                                               [26.43039605],
+                                               [30.76371366]]),
+
+                      expected_funl=numpy.array([-28.44677132, -24.99785984,
+                                                 -22.16855376, -18.72136195,
+                                                 -15.89423937, -12.45154942,
+                                                 -9.63133158, -6.20801301,
+                                                 -3.43727232, -0.46353338])
+                      )
+
+test2_2 = StructTest2(bounds=[(0, 4.5)],
+                      expected_x=[1.53567906],
+                      expected_fun=[-28.44677132],
+                      expected_xl=numpy.array([[1.53567906]]),
+                      expected_funl=numpy.array([-28.44677132])
+                      )
+
+
+class StructTest3(StructTestFunction):
+    """
+    Hock and Schittkowski 18 problem (HS18). Hoch and Schittkowski (1981)
+    http://www.ai7.uni-bayreuth.de/test_problem_coll.pdf
+    Minimize: f = 0.01 * (x_1)**2 + (x_2)**2
+
+    Subject to: x_1 * x_2 - 25.0 >= 0,
+                (x_1)**2 + (x_2)**2 - 25.0 >= 0,
+                2 <= x_1 <= 50,
+                0 <= x_2 <= 50.
+
+    Approx. Answer:
+        f([(250)**0.5 , (2.5)**0.5]) = 5.0
+
+
+    """
+
+    # amended to test vectorisation of constraints
+    def f(self, x):
+        return 0.01 * (x[0]) ** 2 + (x[1]) ** 2
+
+    def g1(x):
+        return x[0] * x[1] - 25.0
+
+    def g2(x):
+        return x[0] ** 2 + x[1] ** 2 - 25.0
+
+    # g = (g1, g2)
+    # cons = wrap_constraints(g)
+
+    def g(x):
+        return x[0] * x[1] - 25.0, x[0] ** 2 + x[1] ** 2 - 25.0
+
+    # this checks that shgo can be sent new-style constraints
+    __nlc = NonlinearConstraint(g, 0, np.inf)
+    cons = (__nlc,)
+
+test3_1 = StructTest3(bounds=[(2, 50), (0, 50)],
+                      expected_x=[250 ** 0.5, 2.5 ** 0.5],
+                      expected_fun=5.0
+                      )
+
+
+class StructTest4(StructTestFunction):
+    """
+    Hock and Schittkowski 11 problem (HS11). Hoch and Schittkowski (1981)
+
+    NOTE: Did not find in original reference to HS collection, refer to
+          Henderson (2015) problem 7 instead. 02.03.2016
+    """
+
+    def f(self, x):
+        return ((x[0] - 10) ** 2 + 5 * (x[1] - 12) ** 2 + x[2] ** 4
+                + 3 * (x[3] - 11) ** 2 + 10 * x[4] ** 6 + 7 * x[5] ** 2 + x[
+                    6] ** 4
+                - 4 * x[5] * x[6] - 10 * x[5] - 8 * x[6]
+                )
+
+    def g1(x):
+        return -(2 * x[0] ** 2 + 3 * x[1] ** 4 + x[2] + 4 * x[3] ** 2
+                 + 5 * x[4] - 127)
+
+    def g2(x):
+        return -(7 * x[0] + 3 * x[1] + 10 * x[2] ** 2 + x[3] - x[4] - 282.0)
+
+    def g3(x):
+        return -(23 * x[0] + x[1] ** 2 + 6 * x[5] ** 2 - 8 * x[6] - 196)
+
+    def g4(x):
+        return -(4 * x[0] ** 2 + x[1] ** 2 - 3 * x[0] * x[1] + 2 * x[2] ** 2
+                 + 5 * x[5] - 11 * x[6])
+
+    g = (g1, g2, g3, g4)
+
+    cons = wrap_constraints(g)
+
+
+test4_1 = StructTest4(bounds=[(-10, 10), ] * 7,
+                      expected_x=[2.330499, 1.951372, -0.4775414,
+                                  4.365726, -0.6244870, 1.038131, 1.594227],
+                      expected_fun=680.6300573
+                      )
+
+
+class StructTest5(StructTestFunction):
+    def f(self, x):
+        return (-(x[1] + 47.0)
+                * numpy.sin(numpy.sqrt(abs(x[0] / 2.0 + (x[1] + 47.0))))
+                - x[0] * numpy.sin(numpy.sqrt(abs(x[0] - (x[1] + 47.0))))
+                )
+
+    g = None
+    cons = wrap_constraints(g)
+
+
+test5_1 = StructTest5(bounds=[(-512, 512), (-512, 512)],
+                      expected_fun=[-959.64066272085051],
+                      expected_x=[512., 404.23180542])
+
+
+class StructTestLJ(StructTestFunction):
+    """
+    LennardJones objective function. Used to test symmetry constraints
+    settings.
+    """
+
+    def f(self, x, *args):
+        print(f'x = {x}')
+        self.N = args[0]
+        k = int(self.N / 3)
+        s = 0.0
+
+        for i in range(k - 1):
+            for j in range(i + 1, k):
+                a = 3 * i
+                b = 3 * j
+                xd = x[a] - x[b]
+                yd = x[a + 1] - x[b + 1]
+                zd = x[a + 2] - x[b + 2]
+                ed = xd * xd + yd * yd + zd * zd
+                ud = ed * ed * ed
+                if ed > 0.0:
+                    s += (1.0 / ud - 2.0) / ud
+
+        return s
+
+    g = None
+    cons = wrap_constraints(g)
+
+
+N = 6
+boundsLJ = list(zip([-4.0] * 6, [4.0] * 6))
+
+testLJ = StructTestLJ(bounds=boundsLJ,
+                      expected_fun=[-1.0],
+                      expected_x=None,
+                      # expected_x=[-2.71247337e-08,
+                      #            -2.71247337e-08,
+                      #            -2.50000222e+00,
+                      #            -2.71247337e-08,
+                      #            -2.71247337e-08,
+                      #            -1.50000222e+00]
+                      )
+
+
+class StructTestS(StructTestFunction):
+    def f(self, x):
+        return ((x[0] - 0.5) ** 2 + (x[1] - 0.5) ** 2
+                + (x[2] - 0.5) ** 2 + (x[3] - 0.5) ** 2)
+
+    g = None
+    cons = wrap_constraints(g)
+
+
+test_s = StructTestS(bounds=[(0, 2.0), ] * 4,
+                     expected_fun=0.0,
+                     expected_x=numpy.ones(4) - 0.5
+                     )
+
+
+class StructTestTable(StructTestFunction):
+    def f(self, x):
+        if x[0] == 3.0 and x[1] == 3.0:
+            return 50
+        else:
+            return 100
+
+    g = None
+    cons = wrap_constraints(g)
+
+
+test_table = StructTestTable(bounds=[(-10, 10), (-10, 10)],
+                             expected_fun=[50],
+                             expected_x=[3.0, 3.0])
+
+
+class StructTestInfeasible(StructTestFunction):
+    """
+    Test function with no feasible domain.
+    """
+
+    def f(self, x, *args):
+        return x[0] ** 2 + x[1] ** 2
+
+    def g1(x):
+        return x[0] + x[1] - 1
+
+    def g2(x):
+        return -(x[0] + x[1] - 1)
+
+    def g3(x):
+        return -x[0] + x[1] - 1
+
+    def g4(x):
+        return -(-x[0] + x[1] - 1)
+
+    g = (g1, g2, g3, g4)
+    cons = wrap_constraints(g)
+
+
+test_infeasible = StructTestInfeasible(bounds=[(2, 50), (-1, 1)],
+                                       expected_fun=None,
+                                       expected_x=None
+                                       )
+
+
+@pytest.mark.skip("Not a test")
+def run_test(test, args=(), test_atol=1e-5, n=100, iters=None,
+             callback=None, minimizer_kwargs=None, options=None,
+             sampling_method='sobol', workers=1):
+    res = shgo(test.f, test.bounds, args=args, constraints=test.cons,
+               n=n, iters=iters, callback=callback,
+               minimizer_kwargs=minimizer_kwargs, options=options,
+               sampling_method=sampling_method, workers=workers)
+
+    print(f'res = {res}')
+    logging.info(f'res = {res}')
+    if test.expected_x is not None:
+        numpy.testing.assert_allclose(res.x, test.expected_x,
+                                      rtol=test_atol,
+                                      atol=test_atol)
+
+    # (Optional tests)
+    if test.expected_fun is not None:
+        numpy.testing.assert_allclose(res.fun,
+                                      test.expected_fun,
+                                      atol=test_atol)
+
+    if test.expected_xl is not None:
+        numpy.testing.assert_allclose(res.xl,
+                                      test.expected_xl,
+                                      atol=test_atol)
+
+    if test.expected_funl is not None:
+        numpy.testing.assert_allclose(res.funl,
+                                      test.expected_funl,
+                                      atol=test_atol)
+    return
+
+
+# Base test functions:
+class TestShgoSobolTestFunctions:
+    """
+    Global optimisation tests with Sobol sampling:
+    """
+
+    # Sobol algorithm
+    def test_f1_1_sobol(self):
+        """Multivariate test function 1:
+        x[0]**2 + x[1]**2 with bounds=[(-1, 6), (-1, 6)]"""
+        run_test(test1_1)
+
+    def test_f1_2_sobol(self):
+        """Multivariate test function 1:
+         x[0]**2 + x[1]**2 with bounds=[(0, 1), (0, 1)]"""
+        run_test(test1_2)
+
+    def test_f1_3_sobol(self):
+        """Multivariate test function 1:
+        x[0]**2 + x[1]**2 with bounds=[(None, None),(None, None)]"""
+        options = {'disp': True}
+        run_test(test1_3, options=options)
+
+    def test_f2_1_sobol(self):
+        """Univariate test function on
+        f(x) = (x - 30) * sin(x) with bounds=[(0, 60)]"""
+        run_test(test2_1)
+
+    def test_f2_2_sobol(self):
+        """Univariate test function on
+        f(x) = (x - 30) * sin(x) bounds=[(0, 4.5)]"""
+        run_test(test2_2)
+
+    def test_f3_sobol(self):
+        """NLP: Hock and Schittkowski problem 18"""
+        run_test(test3_1)
+
+    @pytest.mark.slow
+    def test_f4_sobol(self):
+        """NLP: (High dimensional) Hock and Schittkowski 11 problem (HS11)"""
+        options = {'infty_constraints': False}
+        # run_test(test4_1, n=990, options=options)
+        run_test(test4_1, n=990 * 2, options=options)
+
+    def test_f5_1_sobol(self):
+        """NLP: Eggholder, multimodal"""
+        # run_test(test5_1, n=30)
+        run_test(test5_1, n=60)
+
+    def test_f5_2_sobol(self):
+        """NLP: Eggholder, multimodal"""
+        # run_test(test5_1, n=60, iters=5)
+        run_test(test5_1, n=60, iters=5)
+
+        # def test_t911(self):
+        #    """1D tabletop function"""
+        #    run_test(test11_1)
+
+
+class TestShgoSimplicialTestFunctions:
+    """
+    Global optimisation tests with Simplicial sampling:
+    """
+
+    def test_f1_1_simplicial(self):
+        """Multivariate test function 1:
+        x[0]**2 + x[1]**2 with bounds=[(-1, 6), (-1, 6)]"""
+        run_test(test1_1, n=1, sampling_method='simplicial')
+
+    def test_f1_2_simplicial(self):
+        """Multivariate test function 1:
+        x[0]**2 + x[1]**2 with bounds=[(0, 1), (0, 1)]"""
+        run_test(test1_2, n=1, sampling_method='simplicial')
+
+    def test_f1_3_simplicial(self):
+        """Multivariate test function 1: x[0]**2 + x[1]**2
+        with bounds=[(None, None),(None, None)]"""
+        run_test(test1_3, n=5, sampling_method='simplicial')
+
+    def test_f2_1_simplicial(self):
+        """Univariate test function on
+        f(x) = (x - 30) * sin(x) with bounds=[(0, 60)]"""
+        options = {'minimize_every_iter': False}
+        run_test(test2_1, n=200, iters=7, options=options,
+                 sampling_method='simplicial')
+
+    def test_f2_2_simplicial(self):
+        """Univariate test function on
+        f(x) = (x - 30) * sin(x) bounds=[(0, 4.5)]"""
+        run_test(test2_2, n=1, sampling_method='simplicial')
+
+    def test_f3_simplicial(self):
+        """NLP: Hock and Schittkowski problem 18"""
+        run_test(test3_1, n=1, sampling_method='simplicial')
+
+    @pytest.mark.slow
+    def test_f4_simplicial(self):
+        """NLP: (High dimensional) Hock and Schittkowski 11 problem (HS11)"""
+        run_test(test4_1, n=1, sampling_method='simplicial')
+
+    def test_lj_symmetry_old(self):
+        """LJ: Symmetry-constrained test function"""
+        options = {'symmetry': True,
+                   'disp': True}
+        args = (6,)  # Number of atoms
+        run_test(testLJ, args=args, n=300,
+                 options=options, iters=1,
+                 sampling_method='simplicial')
+
+    def test_f5_1_lj_symmetry(self):
+        """LJ: Symmetry constrained test function"""
+        options = {'symmetry': [0, ] * 6,
+                   'disp': True}
+        args = (6,)  # No. of atoms
+
+        run_test(testLJ, args=args, n=300,
+                 options=options, iters=1,
+                 sampling_method='simplicial')
+
+    def test_f5_2_cons_symmetry(self):
+        """Symmetry constrained test function"""
+        options = {'symmetry': [0, 0],
+                   'disp': True}
+
+        run_test(test1_1, n=200,
+                 options=options, iters=1,
+                 sampling_method='simplicial')
+
+    def test_f5_3_cons_symmetry(self):
+        """Assymmetrically constrained test function"""
+        options = {'symmetry': [0, 0, 0, 3],
+                   'disp': True}
+
+        run_test(test_s, n=10000,
+                 options=options,
+                 iters=1,
+                 sampling_method='simplicial')
+
+    @pytest.mark.skip("Not a test")
+    def test_f0_min_variance(self):
+        """Return a minimum on a perfectly symmetric problem, based on
+            gh10429"""
+        avg = 0.5  # Given average value of x
+        cons = {'type': 'eq', 'fun': lambda x: numpy.mean(x) - avg}
+
+        # Minimize the variance of x under the given constraint
+        res = shgo(numpy.var, bounds=6 * [(0, 1)], constraints=cons)
+        assert res.success
+        assert_allclose(res.fun, 0, atol=1e-15)
+        assert_allclose(res.x, 0.5)
+
+    @pytest.mark.skip("Not a test")
+    def test_f0_min_variance_1D(self):
+        """Return a minimum on a perfectly symmetric 1D problem, based on
+            gh10538"""
+
+        def fun(x):
+            return x * (x - 1.0) * (x - 0.5)
+
+        bounds = [(0, 1)]
+        res = shgo(fun, bounds=bounds)
+        ref = minimize_scalar(fun, bounds=bounds[0])
+        assert res.success
+        assert_allclose(res.fun, ref.fun)
+        assert_allclose(res.x, ref.x, rtol=1e-6)
+
+# Argument test functions
+class TestShgoArguments:
+    def test_1_1_simpl_iter(self):
+        """Iterative simplicial sampling on TestFunction 1 (multivariate)"""
+        run_test(test1_2, n=None, iters=2, sampling_method='simplicial')
+
+    def test_1_2_simpl_iter(self):
+        """Iterative simplicial on TestFunction 2 (univariate)"""
+        options = {'minimize_every_iter': False}
+        run_test(test2_1, n=None, iters=9, options=options,
+                 sampling_method='simplicial')
+
+    def test_2_1_sobol_iter(self):
+        """Iterative Sobol sampling on TestFunction 1 (multivariate)"""
+        run_test(test1_2, n=None, iters=1, sampling_method='sobol')
+
+    def test_2_2_sobol_iter(self):
+        """Iterative Sobol sampling on TestFunction 2 (univariate)"""
+        res = shgo(test2_1.f, test2_1.bounds, constraints=test2_1.cons,
+                   n=None, iters=1, sampling_method='sobol')
+
+        numpy.testing.assert_allclose(res.x, test2_1.expected_x, rtol=1e-5,
+                                      atol=1e-5)
+        numpy.testing.assert_allclose(res.fun, test2_1.expected_fun, atol=1e-5)
+
+    def test_3_1_disp_simplicial(self):
+        """Iterative sampling on TestFunction 1 and 2  (multi and univariate)
+        """
+
+        def callback_func(x):
+            print("Local minimization callback test")
+
+        for test in [test1_1, test2_1]:
+            shgo(test.f, test.bounds, iters=1,
+                 sampling_method='simplicial',
+                 callback=callback_func, options={'disp': True})
+            shgo(test.f, test.bounds, n=1, sampling_method='simplicial',
+                 callback=callback_func, options={'disp': True})
+
+    def test_3_2_disp_sobol(self):
+        """Iterative sampling on TestFunction 1 and 2 (multi and univariate)"""
+
+        def callback_func(x):
+            print("Local minimization callback test")
+
+        for test in [test1_1, test2_1]:
+            shgo(test.f, test.bounds, iters=1, sampling_method='sobol',
+                 callback=callback_func, options={'disp': True})
+
+            shgo(test.f, test.bounds, n=1, sampling_method='simplicial',
+                 callback=callback_func, options={'disp': True})
+
+    def test_args_gh14589(self):
+        """Using `args` used to cause `shgo` to fail; see #14589, #15986,
+        #16506"""
+        res = shgo(func=lambda x, y, z: x * z + y, bounds=[(0, 3)], args=(1, 2)
+                   )
+        ref = shgo(func=lambda x: 2 * x + 1, bounds=[(0, 3)])
+        assert_allclose(res.fun, ref.fun)
+        assert_allclose(res.x, ref.x)
+
+    @pytest.mark.slow
+    def test_4_1_known_f_min(self):
+        """Test known function minima stopping criteria"""
+        # Specify known function value
+        options = {'f_min': test4_1.expected_fun,
+                   'f_tol': 1e-6,
+                   'minimize_every_iter': True}
+        # TODO: Make default n higher for faster tests
+        run_test(test4_1, n=None, test_atol=1e-5, options=options,
+                 sampling_method='simplicial')
+
+    @pytest.mark.slow
+    def test_4_2_known_f_min(self):
+        """Test Global mode limiting local evaluations"""
+        options = {  # Specify known function value
+            'f_min': test4_1.expected_fun,
+            'f_tol': 1e-6,
+            # Specify number of local iterations to perform
+            'minimize_every_iter': True,
+            'local_iter': 1}
+
+        run_test(test4_1, n=None, test_atol=1e-5, options=options,
+                 sampling_method='simplicial')
+
+    def test_4_4_known_f_min(self):
+        """Test Global mode limiting local evaluations for 1D funcs"""
+        options = {  # Specify known function value
+            'f_min': test2_1.expected_fun,
+            'f_tol': 1e-6,
+            # Specify number of local iterations to perform+
+            'minimize_every_iter': True,
+            'local_iter': 1,
+            'infty_constraints': False}
+
+        res = shgo(test2_1.f, test2_1.bounds, constraints=test2_1.cons,
+                   n=None, iters=None, options=options,
+                   sampling_method='sobol')
+        numpy.testing.assert_allclose(res.x, test2_1.expected_x, rtol=1e-5,
+                                      atol=1e-5)
+
+    def test_5_1_simplicial_argless(self):
+        """Test Default simplicial sampling settings on TestFunction 1"""
+        res = shgo(test1_1.f, test1_1.bounds, constraints=test1_1.cons)
+        numpy.testing.assert_allclose(res.x, test1_1.expected_x, rtol=1e-5,
+                                      atol=1e-5)
+
+    def test_5_2_sobol_argless(self):
+        """Test Default sobol sampling settings on TestFunction 1"""
+        res = shgo(test1_1.f, test1_1.bounds, constraints=test1_1.cons,
+                   sampling_method='sobol')
+        numpy.testing.assert_allclose(res.x, test1_1.expected_x, rtol=1e-5,
+                                      atol=1e-5)
+
+    def test_6_1_simplicial_max_iter(self):
+        """Test that maximum iteration option works on TestFunction 3"""
+        options = {'max_iter': 2}
+        res = shgo(test3_1.f, test3_1.bounds, constraints=test3_1.cons,
+                   options=options, sampling_method='simplicial')
+        numpy.testing.assert_allclose(res.x, test3_1.expected_x, rtol=1e-5,
+                                      atol=1e-5)
+        numpy.testing.assert_allclose(res.fun, test3_1.expected_fun, atol=1e-5)
+
+    def test_6_2_simplicial_min_iter(self):
+        """Test that maximum iteration option works on TestFunction 3"""
+        options = {'min_iter': 2}
+        res = shgo(test3_1.f, test3_1.bounds, constraints=test3_1.cons,
+                   options=options, sampling_method='simplicial')
+        numpy.testing.assert_allclose(res.x, test3_1.expected_x, rtol=1e-5,
+                                      atol=1e-5)
+        numpy.testing.assert_allclose(res.fun, test3_1.expected_fun, atol=1e-5)
+
+    def test_7_1_minkwargs(self):
+        """Test the minimizer_kwargs arguments for solvers with constraints"""
+        # Test solvers
+        for solver in ['COBYLA', 'SLSQP']:
+            # Note that passing global constraints to SLSQP is tested in other
+            # unittests which run test4_1 normally
+            minimizer_kwargs = {'method': solver,
+                                'constraints': test3_1.cons}
+            run_test(test3_1, n=100, test_atol=1e-3,
+                     minimizer_kwargs=minimizer_kwargs,
+                     sampling_method='sobol')
+
+    def test_7_2_minkwargs(self):
+        """Test the minimizer_kwargs default inits"""
+        minimizer_kwargs = {'ftol': 1e-5}
+        options = {'disp': True}  # For coverage purposes
+        SHGO(test3_1.f, test3_1.bounds, constraints=test3_1.cons[0],
+             minimizer_kwargs=minimizer_kwargs, options=options)
+
+    def test_7_3_minkwargs(self):
+        """Test minimizer_kwargs arguments for solvers without constraints"""
+        for solver in ['Nelder-Mead', 'Powell', 'CG', 'BFGS', 'Newton-CG',
+                       'L-BFGS-B', 'TNC', 'dogleg', 'trust-ncg', 'trust-exact',
+                       'trust-krylov']:
+            def jac(x):
+                return numpy.array([2 * x[0], 2 * x[1]]).T
+
+            def hess(x):
+                return numpy.array([[2, 0], [0, 2]])
+
+            minimizer_kwargs = {'method': solver,
+                                'jac': jac,
+                                'hess': hess}
+            logging.info(f"Solver = {solver}")
+            logging.info("=" * 100)
+            run_test(test1_1, n=100, test_atol=1e-3,
+                     minimizer_kwargs=minimizer_kwargs,
+                     sampling_method='sobol')
+
+    def test_8_homology_group_diff(self):
+        options = {'minhgrd': 1,
+                   'minimize_every_iter': True}
+
+        run_test(test1_1, n=None, iters=None, options=options,
+                 sampling_method='simplicial')
+
+    def test_9_cons_g(self):
+        """Test single function constraint passing"""
+        SHGO(test3_1.f, test3_1.bounds, constraints=test3_1.cons[0])
+
+    @pytest.mark.xfail(IS_PYPY and sys.platform == 'win32',
+            reason="Failing and fix in PyPy not planned (see gh-18632)")
+    def test_10_finite_time(self):
+        """Test single function constraint passing"""
+        options = {'maxtime': 1e-15}
+
+        def f(x):
+            time.sleep(1e-14)
+            return 0.0
+
+        res = shgo(f, test1_1.bounds, iters=5, options=options)
+        # Assert that only 1 rather than 5 requested iterations ran:
+        assert res.nit == 1
+
+    def test_11_f_min_0(self):
+        """Test to cover the case where f_lowest == 0"""
+        options = {'f_min': 0.0,
+                   'disp': True}
+        res = shgo(test1_2.f, test1_2.bounds, n=10, iters=None,
+                   options=options, sampling_method='sobol')
+        numpy.testing.assert_equal(0, res.x[0])
+        numpy.testing.assert_equal(0, res.x[1])
+
+    # @nottest
+    @pytest.mark.skip(reason="no way of currently testing this")
+    def test_12_sobol_inf_cons(self):
+        """Test to cover the case where f_lowest == 0"""
+        # TODO: This test doesn't cover anything new, it is unknown what the
+        # original test was intended for as it was never complete. Delete or
+        # replace in the future.
+        options = {'maxtime': 1e-15,
+                   'f_min': 0.0}
+        res = shgo(test1_2.f, test1_2.bounds, n=1, iters=None,
+                   options=options, sampling_method='sobol')
+        numpy.testing.assert_equal(0.0, res.fun)
+
+    def test_13_high_sobol(self):
+        """Test init of high-dimensional sobol sequences"""
+
+        def f(x):
+            return 0
+
+        bounds = [(None, None), ] * 41
+        SHGOc = SHGO(f, bounds, sampling_method='sobol')
+        # SHGOc.sobol_points(2, 50)
+        SHGOc.sampling_function(2, 50)
+
+    def test_14_local_iter(self):
+        """Test limited local iterations for a pseudo-global mode"""
+        options = {'local_iter': 4}
+        run_test(test5_1, n=60, options=options)
+
+    def test_15_min_every_iter(self):
+        """Test minimize every iter options and cover function cache"""
+        options = {'minimize_every_iter': True}
+        run_test(test1_1, n=1, iters=7, options=options,
+                 sampling_method='sobol')
+
+    def test_16_disp_bounds_minimizer(self, capsys):
+        """Test disp=True with minimizers that do not support bounds """
+        options = {'disp': True}
+        minimizer_kwargs = {'method': 'nelder-mead'}
+        run_test(test1_2, sampling_method='simplicial',
+                 options=options, minimizer_kwargs=minimizer_kwargs)
+
+    def test_17_custom_sampling(self):
+        """Test the functionality to add custom sampling methods to shgo"""
+
+        def sample(n, d):
+            return numpy.random.uniform(size=(n, d))
+
+        run_test(test1_1, n=30, sampling_method=sample)
+
+    def test_18_bounds_class(self):
+        # test that new and old bounds yield same result
+        def f(x):
+            return numpy.square(x).sum()
+
+        lb = [-6., 1., -5.]
+        ub = [-1., 3., 5.]
+        bounds_old = list(zip(lb, ub))
+        bounds_new = Bounds(lb, ub)
+
+        res_old_bounds = shgo(f, bounds_old)
+        res_new_bounds = shgo(f, bounds_new)
+
+        assert res_new_bounds.nfev == res_old_bounds.nfev
+        assert res_new_bounds.message == res_old_bounds.message
+        assert res_new_bounds.success == res_old_bounds.success
+        x_opt = numpy.array([-1., 1., 0.])
+        numpy.testing.assert_allclose(res_new_bounds.x, x_opt)
+        numpy.testing.assert_allclose(res_new_bounds.x,
+                                      res_old_bounds.x)
+
+    def test_19_parallelization(self):
+        """Test the functionality to add custom sampling methods to shgo"""
+
+        with Pool(2) as p:
+            run_test(test1_1, n=30, workers=p.map)  # Constrained
+        run_test(test1_1, n=30, workers=map)  # Constrained
+        with Pool(2) as p:
+            run_test(test_s, n=30, workers=p.map)  # Unconstrained
+        run_test(test_s, n=30, workers=map)  # Unconstrained
+
+    def test_20_constrained_args(self):
+        """Test that constraints can be passed to arguments"""
+
+        def eggholder(x):
+            return (-(x[1] + 47.0)
+                    * numpy.sin(numpy.sqrt(abs(x[0] / 2.0 + (x[1] + 47.0))))
+                    - x[0] * numpy.sin(numpy.sqrt(abs(x[0] - (x[1] + 47.0))))
+                    )
+
+        def f(x):  # (cattle-feed)
+            return 24.55 * x[0] + 26.75 * x[1] + 39 * x[2] + 40.50 * x[3]
+
+        bounds = [(0, 1.0), ] * 4
+
+        def g1_modified(x, i):
+            return i * 2.3 * x[0] + i * 5.6 * x[1] + 11.1 * x[2] + 1.3 * x[
+                3] - 5  # >=0
+
+        def g2(x):
+            return (12 * x[0] + 11.9 * x[1] + 41.8 * x[2] + 52.1 * x[3] - 21
+                    - 1.645 * numpy.sqrt(0.28 * x[0] ** 2 + 0.19 * x[1] ** 2
+                                         + 20.5 * x[2] ** 2 + 0.62 * x[3] ** 2)
+                    )  # >=0
+
+        def h1(x):
+            return x[0] + x[1] + x[2] + x[3] - 1  # == 0
+
+        cons = ({'type': 'ineq', 'fun': g1_modified, "args": (0,)},
+                {'type': 'ineq', 'fun': g2},
+                {'type': 'eq', 'fun': h1})
+
+        shgo(f, bounds, n=300, iters=1, constraints=cons)
+        # using constrain with arguments AND sampling method sobol
+        shgo(f, bounds, n=300, iters=1, constraints=cons,
+             sampling_method='sobol')
+
+    def test_21_1_jac_true(self):
+        """Test that shgo can handle objective functions that return the
+        gradient alongside the objective value. Fixes gh-13547"""
+        # previous
+        def func(x):
+            return numpy.sum(numpy.power(x, 2)), 2 * x
+
+        shgo(
+            func,
+            bounds=[[-1, 1], [1, 2]],
+            n=100, iters=5,
+            sampling_method="sobol",
+            minimizer_kwargs={'method': 'SLSQP', 'jac': True}
+        )
+
+        # new
+        def func(x):
+            return numpy.sum(x ** 2), 2 * x
+
+        bounds = [[-1, 1], [1, 2], [-1, 1], [1, 2], [0, 3]]
+
+        res = shgo(func, bounds=bounds, sampling_method="sobol",
+                   minimizer_kwargs={'method': 'SLSQP', 'jac': True})
+        ref = minimize(func, x0=[1, 1, 1, 1, 1], bounds=bounds,
+                       jac=True)
+        assert res.success
+        assert_allclose(res.fun, ref.fun)
+        assert_allclose(res.x, ref.x, atol=1e-15)
+
+    @pytest.mark.parametrize('derivative', ['jac', 'hess', 'hessp'])
+    def test_21_2_derivative_options(self, derivative):
+        """shgo used to raise an error when passing `options` with 'jac'
+        # see gh-12963. check that this is resolved
+        """
+
+        def objective(x):
+            return 3 * x[0] * x[0] + 2 * x[0] + 5
+
+        def gradient(x):
+            return 6 * x[0] + 2
+
+        def hess(x):
+            return 6
+
+        def hessp(x, p):
+            return 6 * p
+
+        derivative_funcs = {'jac': gradient, 'hess': hess, 'hessp': hessp}
+        options = {derivative: derivative_funcs[derivative]}
+        minimizer_kwargs = {'method': 'trust-constr'}
+
+        bounds = [(-100, 100)]
+        res = shgo(objective, bounds, minimizer_kwargs=minimizer_kwargs,
+                   options=options)
+        ref = minimize(objective, x0=[0], bounds=bounds, **minimizer_kwargs,
+                       **options)
+
+        assert res.success
+        numpy.testing.assert_allclose(res.fun, ref.fun)
+        numpy.testing.assert_allclose(res.x, ref.x)
+
+    def test_21_3_hess_options_rosen(self):
+        """Ensure the Hessian gets passed correctly to the local minimizer
+        routine. Previous report gh-14533.
+        """
+        bounds = [(0, 1.6), (0, 1.6), (0, 1.4), (0, 1.4), (0, 1.4)]
+        options = {'jac': rosen_der, 'hess': rosen_hess}
+        minimizer_kwargs = {'method': 'Newton-CG'}
+        res = shgo(rosen, bounds, minimizer_kwargs=minimizer_kwargs,
+                   options=options)
+        ref = minimize(rosen, numpy.zeros(5), method='Newton-CG',
+                       **options)
+        assert res.success
+        assert_allclose(res.fun, ref.fun)
+        assert_allclose(res.x, ref.x, atol=1e-15)
+
+    def test_21_arg_tuple_sobol(self):
+        """shgo used to raise an error when passing `args` with Sobol sampling
+        # see gh-12114. check that this is resolved"""
+
+        def fun(x, k):
+            return x[0] ** k
+
+        constraints = ({'type': 'ineq', 'fun': lambda x: x[0] - 1})
+
+        bounds = [(0, 10)]
+        res = shgo(fun, bounds, args=(1,), constraints=constraints,
+                   sampling_method='sobol')
+        ref = minimize(fun, numpy.zeros(1), bounds=bounds, args=(1,),
+                       constraints=constraints)
+        assert res.success
+        assert_allclose(res.fun, ref.fun)
+        assert_allclose(res.x, ref.x)
+
+
+# Failure test functions
+class TestShgoFailures:
+    def test_1_maxiter(self):
+        """Test failure on insufficient iterations"""
+        options = {'maxiter': 2}
+        res = shgo(test4_1.f, test4_1.bounds, n=2, iters=None,
+                   options=options, sampling_method='sobol')
+
+        numpy.testing.assert_equal(False, res.success)
+        # numpy.testing.assert_equal(4, res.nfev)
+        numpy.testing.assert_equal(4, res.tnev)
+
+    def test_2_sampling(self):
+        """Rejection of unknown sampling method"""
+        assert_raises(ValueError, shgo, test1_1.f, test1_1.bounds,
+                      sampling_method='not_Sobol')
+
+    def test_3_1_no_min_pool_sobol(self):
+        """Check that the routine stops when no minimiser is found
+           after maximum specified function evaluations"""
+        options = {'maxfev': 10,
+                   # 'maxev': 10,
+                   'disp': True}
+        res = shgo(test_table.f, test_table.bounds, n=3, options=options,
+                   sampling_method='sobol')
+        numpy.testing.assert_equal(False, res.success)
+        # numpy.testing.assert_equal(9, res.nfev)
+        numpy.testing.assert_equal(12, res.nfev)
+
+    def test_3_2_no_min_pool_simplicial(self):
+        """Check that the routine stops when no minimiser is found
+           after maximum specified sampling evaluations"""
+        options = {'maxev': 10,
+                   'disp': True}
+        res = shgo(test_table.f, test_table.bounds, n=3, options=options,
+                   sampling_method='simplicial')
+        numpy.testing.assert_equal(False, res.success)
+
+    def test_4_1_bound_err(self):
+        """Specified bounds ub > lb"""
+        bounds = [(6, 3), (3, 5)]
+        assert_raises(ValueError, shgo, test1_1.f, bounds)
+
+    def test_4_2_bound_err(self):
+        """Specified bounds are of the form (lb, ub)"""
+        bounds = [(3, 5, 5), (3, 5)]
+        assert_raises(ValueError, shgo, test1_1.f, bounds)
+
+    def test_5_1_1_infeasible_sobol(self):
+        """Ensures the algorithm terminates on infeasible problems
+           after maxev is exceeded. Use infty constraints option"""
+        options = {'maxev': 100,
+                   'disp': True}
+
+        res = shgo(test_infeasible.f, test_infeasible.bounds,
+                   constraints=test_infeasible.cons, n=100, options=options,
+                   sampling_method='sobol')
+
+        numpy.testing.assert_equal(False, res.success)
+
+    def test_5_1_2_infeasible_sobol(self):
+        """Ensures the algorithm terminates on infeasible problems
+           after maxev is exceeded. Do not use infty constraints option"""
+        options = {'maxev': 100,
+                   'disp': True,
+                   'infty_constraints': False}
+
+        res = shgo(test_infeasible.f, test_infeasible.bounds,
+                   constraints=test_infeasible.cons, n=100, options=options,
+                   sampling_method='sobol')
+
+        numpy.testing.assert_equal(False, res.success)
+
+    def test_5_2_infeasible_simplicial(self):
+        """Ensures the algorithm terminates on infeasible problems
+           after maxev is exceeded."""
+        options = {'maxev': 1000,
+                   'disp': False}
+
+        res = shgo(test_infeasible.f, test_infeasible.bounds,
+                   constraints=test_infeasible.cons, n=100, options=options,
+                   sampling_method='simplicial')
+
+        numpy.testing.assert_equal(False, res.success)
+
+    def test_6_1_lower_known_f_min(self):
+        """Test Global mode limiting local evaluations with f* too high"""
+        options = {  # Specify known function value
+            'f_min': test2_1.expected_fun + 2.0,
+            'f_tol': 1e-6,
+            # Specify number of local iterations to perform+
+            'minimize_every_iter': True,
+            'local_iter': 1,
+            'infty_constraints': False}
+        args = (test2_1.f, test2_1.bounds)
+        kwargs = {'constraints': test2_1.cons,
+                  'n': None,
+                  'iters': None,
+                  'options': options,
+                  'sampling_method': 'sobol'
+                  }
+        warns(UserWarning, shgo, *args, **kwargs)
+
+    def test(self):
+        from scipy.optimize import rosen, shgo
+        bounds = [(0, 2), (0, 2), (0, 2), (0, 2), (0, 2)]
+
+        def fun(x):
+            fun.nfev += 1
+            return rosen(x)
+
+        fun.nfev = 0
+
+        result = shgo(fun, bounds)
+        print(result.x, result.fun, fun.nfev)  # 50
+
+
+# Returns
+class TestShgoReturns:
+    def test_1_nfev_simplicial(self):
+        bounds = [(0, 2), (0, 2), (0, 2), (0, 2), (0, 2)]
+
+        def fun(x):
+            fun.nfev += 1
+            return rosen(x)
+
+        fun.nfev = 0
+
+        result = shgo(fun, bounds)
+        numpy.testing.assert_equal(fun.nfev, result.nfev)
+
+    def test_1_nfev_sobol(self):
+        bounds = [(0, 2), (0, 2), (0, 2), (0, 2), (0, 2)]
+
+        def fun(x):
+            fun.nfev += 1
+            return rosen(x)
+
+        fun.nfev = 0
+
+        result = shgo(fun, bounds, sampling_method='sobol')
+        numpy.testing.assert_equal(fun.nfev, result.nfev)
+
+
+def test_vector_constraint():
+    # gh15514
+    def quad(x):
+        x = np.asarray(x)
+        return [np.sum(x ** 2)]
+
+    nlc = NonlinearConstraint(quad, [2.2], [3])
+    oldc = new_constraint_to_old(nlc, np.array([1.0, 1.0]))
+
+    res = shgo(rosen, [(0, 10), (0, 10)], constraints=oldc, sampling_method='sobol')
+    assert np.all(np.sum((res.x)**2) >= 2.2)
+    assert np.all(np.sum((res.x) ** 2) <= 3.0)
+    assert res.success
+
+
+@pytest.mark.filterwarnings("ignore:delta_grad")
+def test_trust_constr():
+    def quad(x):
+        x = np.asarray(x)
+        return [np.sum(x ** 2)]
+
+    nlc = NonlinearConstraint(quad, [2.6], [3])
+    minimizer_kwargs = {'method': 'trust-constr'}
+    # note that we don't supply the constraints in minimizer_kwargs,
+    # so if the final result obeys the constraints we know that shgo
+    # passed them on to 'trust-constr'
+    res = shgo(
+        rosen,
+        [(0, 10), (0, 10)],
+        constraints=nlc,
+        sampling_method='sobol',
+        minimizer_kwargs=minimizer_kwargs
+    )
+    assert np.all(np.sum((res.x)**2) >= 2.6)
+    assert np.all(np.sum((res.x) ** 2) <= 3.0)
+    assert res.success
+
+
+def test_equality_constraints():
+    # gh16260
+    bounds = [(0.9, 4.0)] * 2  # Constrain probabilities to 0 and 1.
+
+    def faulty(x):
+        return x[0] + x[1]
+
+    nlc = NonlinearConstraint(faulty, 3.9, 3.9)
+    res = shgo(rosen, bounds=bounds, constraints=nlc)
+    assert_allclose(np.sum(res.x), 3.9)
+
+    def faulty(x):
+        return x[0] + x[1] - 3.9
+
+    constraints = {'type': 'eq', 'fun': faulty}
+    res = shgo(rosen, bounds=bounds, constraints=constraints)
+    assert_allclose(np.sum(res.x), 3.9)
+
+    bounds = [(0, 1.0)] * 4
+    # sum of variable should equal 1.
+    def faulty(x):
+        return x[0] + x[1] + x[2] + x[3] - 1
+
+    # options = {'minimize_every_iter': True, 'local_iter':10}
+    constraints = {'type': 'eq', 'fun': faulty}
+    res = shgo(
+        lambda x: - np.prod(x),
+        bounds=bounds,
+        constraints=constraints,
+        sampling_method='sobol'
+    )
+    assert_allclose(np.sum(res.x), 1.0)
+
+def test_gh16971():
+    def cons(x):
+        return np.sum(x**2) - 0
+
+    c = {'fun': cons, 'type': 'ineq'}
+    minimizer_kwargs = {
+        'method': 'COBYLA',
+        'options': {'rhobeg': 5, 'tol': 5e-1, 'catol': 0.05}
+    }
+
+    s = SHGO(
+        rosen, [(0, 10)]*2, constraints=c, minimizer_kwargs=minimizer_kwargs
+    )
+
+    assert s.minimizer_kwargs['method'].lower() == 'cobyla'
+    assert s.minimizer_kwargs['options']['catol'] == 0.05

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test__spectral.py

@@ -0,0 +1,226 @@
+import itertools
+
+import numpy as np
+from numpy import exp
+from numpy.testing import assert_, assert_equal
+
+from scipy.optimize import root
+
+
+def test_performance():
+    # Compare performance results to those listed in
+    # [Cheng & Li, IMA J. Num. An. 29, 814 (2008)]
+    # and
+    # [W. La Cruz, J.M. Martinez, M. Raydan, Math. Comp. 75, 1429 (2006)].
+    # and those produced by dfsane.f from M. Raydan's website.
+    #
+    # Where the results disagree, the largest limits are taken.
+
+    e_a = 1e-5
+    e_r = 1e-4
+
+    table_1 = [
+        dict(F=F_1, x0=x0_1, n=1000, nit=5, nfev=5),
+        dict(F=F_1, x0=x0_1, n=10000, nit=2, nfev=2),
+        dict(F=F_2, x0=x0_2, n=500, nit=11, nfev=11),
+        dict(F=F_2, x0=x0_2, n=2000, nit=11, nfev=11),
+        # dict(F=F_4, x0=x0_4, n=999, nit=243, nfev=1188) removed:
+        # too sensitive to rounding errors
+        # Results from dfsane.f; papers list nit=3, nfev=3
+        dict(F=F_6, x0=x0_6, n=100, nit=6, nfev=6),
+        # Must have n%3==0, typo in papers?
+        dict(F=F_7, x0=x0_7, n=99, nit=23, nfev=29),
+        # Must have n%3==0, typo in papers?
+        dict(F=F_7, x0=x0_7, n=999, nit=23, nfev=29),
+        # Results from dfsane.f; papers list nit=nfev=6?
+        dict(F=F_9, x0=x0_9, n=100, nit=12, nfev=18),
+        dict(F=F_9, x0=x0_9, n=1000, nit=12, nfev=18),
+        # Results from dfsane.f; papers list nit=2, nfev=12
+        dict(F=F_10, x0=x0_10, n=1000, nit=5, nfev=5),
+    ]
+
+    # Check also scaling invariance
+    for xscale, yscale, line_search in itertools.product(
+        [1.0, 1e-10, 1e10], [1.0, 1e-10, 1e10], ['cruz', 'cheng']
+    ):
+        for problem in table_1:
+            n = problem['n']
+            def func(x, n):
+                return yscale * problem['F'](x / xscale, n)
+            args = (n,)
+            x0 = problem['x0'](n) * xscale
+
+            fatol = np.sqrt(n) * e_a * yscale + e_r * np.linalg.norm(func(x0, n))
+
+            sigma_eps = 1e-10 * min(yscale/xscale, xscale/yscale)
+            sigma_0 = xscale/yscale
+
+            with np.errstate(over='ignore'):
+                sol = root(func, x0, args=args,
+                           options=dict(ftol=0, fatol=fatol, maxfev=problem['nfev'] + 1,
+                                        sigma_0=sigma_0, sigma_eps=sigma_eps,
+                                        line_search=line_search),
+                           method='DF-SANE')
+
+            err_msg = repr(
+                [xscale, yscale, line_search, problem, np.linalg.norm(func(sol.x, n)),
+                 fatol, sol.success, sol.nit, sol.nfev]
+            )
+            assert sol.success, err_msg
+            # nfev+1: dfsane.f doesn't count first eval
+            assert sol.nfev <= problem['nfev'] + 1, err_msg
+            assert sol.nit <= problem['nit'], err_msg
+            assert np.linalg.norm(func(sol.x, n)) <= fatol, err_msg
+
+
+def test_complex():
+    def func(z):
+        return z**2 - 1 + 2j
+    x0 = 2.0j
+
+    ftol = 1e-4
+    sol = root(func, x0, tol=ftol, method='DF-SANE')
+
+    assert_(sol.success)
+
+    f0 = np.linalg.norm(func(x0))
+    fx = np.linalg.norm(func(sol.x))
+    assert_(fx <= ftol*f0)
+
+
+def test_linear_definite():
+    # The DF-SANE paper proves convergence for "strongly isolated"
+    # solutions.
+    #
+    # For linear systems F(x) = A x - b = 0, with A positive or
+    # negative definite, the solution is strongly isolated.
+
+    def check_solvability(A, b, line_search='cruz'):
+        def func(x):
+            return A.dot(x) - b
+        xp = np.linalg.solve(A, b)
+        eps = np.linalg.norm(func(xp)) * 1e3
+        sol = root(
+            func, b,
+            options=dict(fatol=eps, ftol=0, maxfev=17523, line_search=line_search),
+            method='DF-SANE',
+        )
+        assert_(sol.success)
+        assert_(np.linalg.norm(func(sol.x)) <= eps)
+
+    n = 90
+
+    # Test linear pos.def. system
+    np.random.seed(1234)
+    A = np.arange(n*n).reshape(n, n)
+    A = A + n*n * np.diag(1 + np.arange(n))
+    assert_(np.linalg.eigvals(A).min() > 0)
+    b = np.arange(n) * 1.0
+    check_solvability(A, b, 'cruz')
+    check_solvability(A, b, 'cheng')
+
+    # Test linear neg.def. system
+    check_solvability(-A, b, 'cruz')
+    check_solvability(-A, b, 'cheng')
+
+
+def test_shape():
+    def f(x, arg):
+        return x - arg
+
+    for dt in [float, complex]:
+        x = np.zeros([2,2])
+        arg = np.ones([2,2], dtype=dt)
+
+        sol = root(f, x, args=(arg,), method='DF-SANE')
+        assert_(sol.success)
+        assert_equal(sol.x.shape, x.shape)
+
+
+# Some of the test functions and initial guesses listed in
+# [W. La Cruz, M. Raydan. Optimization Methods and Software, 18, 583 (2003)]
+
+def F_1(x, n):
+    g = np.zeros([n])
+    i = np.arange(2, n+1)
+    g[0] = exp(x[0] - 1) - 1
+    g[1:] = i*(exp(x[1:] - 1) - x[1:])
+    return g
+
+def x0_1(n):
+    x0 = np.empty([n])
+    x0.fill(n/(n-1))
+    return x0
+
+def F_2(x, n):
+    g = np.zeros([n])
+    i = np.arange(2, n+1)
+    g[0] = exp(x[0]) - 1
+    g[1:] = 0.1*i*(exp(x[1:]) + x[:-1] - 1)
+    return g
+
+def x0_2(n):
+    x0 = np.empty([n])
+    x0.fill(1/n**2)
+    return x0
+
+
+def F_4(x, n):  # skip name check
+    assert_equal(n % 3, 0)
+    g = np.zeros([n])
+    # Note: the first line is typoed in some of the references;
+    # correct in original [Gasparo, Optimization Meth. 13, 79 (2000)]
+    g[::3] = 0.6 * x[::3] + 1.6 * x[1::3]**3 - 7.2 * x[1::3]**2 + 9.6 * x[1::3] - 4.8
+    g[1::3] = (0.48 * x[::3] - 0.72 * x[1::3]**3 + 3.24 * x[1::3]**2 - 4.32 * x[1::3]
+               - x[2::3] + 0.2 * x[2::3]**3 + 2.16)
+    g[2::3] = 1.25 * x[2::3] - 0.25*x[2::3]**3
+    return g
+
+
+def x0_4(n):  # skip name check
+    assert_equal(n % 3, 0)
+    x0 = np.array([-1, 1/2, -1] * (n//3))
+    return x0
+
+def F_6(x, n):
+    c = 0.9
+    mu = (np.arange(1, n+1) - 0.5)/n
+    return x - 1/(1 - c/(2*n) * (mu[:,None]*x / (mu[:,None] + mu)).sum(axis=1))
+
+def x0_6(n):
+    return np.ones([n])
+
+def F_7(x, n):
+    assert_equal(n % 3, 0)
+
+    def phi(t):
+        v = 0.5*t - 2
+        v[t > -1] = ((-592*t**3 + 888*t**2 + 4551*t - 1924)/1998)[t > -1]
+        v[t >= 2] = (0.5*t + 2)[t >= 2]
+        return v
+    g = np.zeros([n])
+    g[::3] = 1e4 * x[1::3]**2 - 1
+    g[1::3] = exp(-x[::3]) + exp(-x[1::3]) - 1.0001
+    g[2::3] = phi(x[2::3])
+    return g
+
+def x0_7(n):
+    assert_equal(n % 3, 0)
+    return np.array([1e-3, 18, 1] * (n//3))
+
+def F_9(x, n):
+    g = np.zeros([n])
+    i = np.arange(2, n)
+    g[0] = x[0]**3/3 + x[1]**2/2
+    g[1:-1] = -x[1:-1]**2/2 + i*x[1:-1]**3/3 + x[2:]**2/2
+    g[-1] = -x[-1]**2/2 + n*x[-1]**3/3
+    return g
+
+def x0_9(n):
+    return np.ones([n])
+
+def F_10(x, n):
+    return np.log(1 + x) - x/n
+
+def x0_10(n):
+    return np.ones([n])

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_bracket.py

@@ -0,0 +1,780 @@
+import pytest
+
+import numpy as np
+from numpy.testing import assert_array_less, assert_allclose, assert_equal
+
+from scipy.optimize._bracket import _bracket_root, _bracket_minimum, _ELIMITS
+import scipy._lib._elementwise_iterative_method as eim
+from scipy import stats
+
+class TestBracketRoot:
+    @pytest.mark.parametrize("seed", (615655101, 3141866013, 238075752))
+    @pytest.mark.parametrize("use_xmin", (False, True))
+    @pytest.mark.parametrize("other_side", (False, True))
+    @pytest.mark.parametrize("fix_one_side", (False, True))
+    def test_nfev_expected(self, seed, use_xmin, other_side, fix_one_side):
+        # Property-based test to confirm that _bracket_root is behaving as
+        # expected. The basic case is when root < a < b.
+        # The number of times bracket expands (per side) can be found by
+        # setting the expression for the left endpoint of the bracket to the
+        # root of f (x=0), solving for i, and rounding up. The corresponding
+        # lower and upper ends of the bracket are found by plugging this back
+        # into the expression for the ends of the bracket.
+        # `other_side=True` is the case that a < b < root
+        # Special cases like a < root < b are tested separately
+
+        rng = np.random.default_rng(seed)
+        xl0, d, factor = rng.random(size=3) * [1e5, 10, 5]
+        factor = 1 + factor  # factor must be greater than 1
+        xr0 = xl0 + d  # xr0 must be greater than a in basic case
+
+        def f(x):
+            f.count += 1
+            return x  # root is 0
+
+        if use_xmin:
+            xmin = -rng.random()
+            n = np.ceil(np.log(-(xl0 - xmin) / xmin) / np.log(factor))
+            l, u = xmin + (xl0 - xmin)*factor**-n, xmin + (xl0 - xmin)*factor**-(n - 1)
+            kwargs = dict(xl0=xl0, xr0=xr0, factor=factor, xmin=xmin)
+        else:
+            n = np.ceil(np.log(xr0/d) / np.log(factor))
+            l, u = xr0 - d*factor**n, xr0 - d*factor**(n-1)
+            kwargs = dict(xl0=xl0, xr0=xr0, factor=factor)
+
+        if other_side:
+            kwargs['xl0'], kwargs['xr0'] = -kwargs['xr0'], -kwargs['xl0']
+            l, u = -u, -l
+            if 'xmin' in kwargs:
+                kwargs['xmax'] = -kwargs.pop('xmin')
+
+        if fix_one_side:
+            if other_side:
+                kwargs['xmin'] = -xr0
+            else:
+                kwargs['xmax'] = xr0
+
+        f.count = 0
+        res = _bracket_root(f, **kwargs)
+
+        # Compare reported number of function evaluations `nfev` against
+        # reported `nit`, actual function call count `f.count`, and theoretical
+        # number of expansions `n`.
+        # When both sides are free, these get multiplied by 2 because function
+        # is evaluated on the left and the right each iteration.
+        # When one side is fixed, however, we add one: on the right side, the
+        # function gets evaluated once at b.
+        # Add 1 to `n` and `res.nit` because function evaluations occur at
+        # iterations *0*, 1, ..., `n`. Subtract 1 from `f.count` because
+        # function is called separately for left and right in iteration 0.
+        if not fix_one_side:
+            assert res.nfev == 2*(res.nit+1) == 2*(f.count-1) == 2*(n + 1)
+        else:
+            assert res.nfev == (res.nit+1)+1 == (f.count-1)+1 == (n+1)+1
+
+        # Compare reported bracket to theoretical bracket and reported function
+        # values to function evaluated at bracket.
+        bracket = np.asarray([res.xl, res.xr])
+        assert_allclose(bracket, (l, u))
+        f_bracket = np.asarray([res.fl, res.fr])
+        assert_allclose(f_bracket, f(bracket))
+
+        # Check that bracket is valid and that status and success are correct
+        assert res.xr > res.xl
+        signs = np.sign(f_bracket)
+        assert signs[0] == -signs[1]
+        assert res.status == 0
+        assert res.success
+
+    def f(self, q, p):
+        return stats.norm.cdf(q) - p
+
+    @pytest.mark.parametrize('p', [0.6, np.linspace(0.05, 0.95, 10)])
+    @pytest.mark.parametrize('xmin', [-5, None])
+    @pytest.mark.parametrize('xmax', [5, None])
+    @pytest.mark.parametrize('factor', [1.2, 2])
+    def test_basic(self, p, xmin, xmax, factor):
+        # Test basic functionality to bracket root (distribution PPF)
+        res = _bracket_root(self.f, -0.01, 0.01, xmin=xmin, xmax=xmax,
+                            factor=factor, args=(p,))
+        assert_equal(-np.sign(res.fl), np.sign(res.fr))
+
+    @pytest.mark.parametrize('shape', [tuple(), (12,), (3, 4), (3, 2, 2)])
+    def test_vectorization(self, shape):
+        # Test for correct functionality, output shapes, and dtypes for various
+        # input shapes.
+        p = np.linspace(-0.05, 1.05, 12).reshape(shape) if shape else 0.6
+        args = (p,)
+        maxiter = 10
+
+        @np.vectorize
+        def bracket_root_single(xl0, xr0, xmin, xmax, factor, p):
+            return _bracket_root(self.f, xl0, xr0, xmin=xmin, xmax=xmax,
+                                 factor=factor, args=(p,),
+                                 maxiter=maxiter)
+
+        def f(*args, **kwargs):
+            f.f_evals += 1
+            return self.f(*args, **kwargs)
+        f.f_evals = 0
+
+        rng = np.random.default_rng(2348234)
+        xl0 = -rng.random(size=shape)
+        xr0 = rng.random(size=shape)
+        xmin, xmax = 1e3*xl0, 1e3*xr0
+        if shape:  # make some elements un
+            i = rng.random(size=shape) > 0.5
+            xmin[i], xmax[i] = -np.inf, np.inf
+        factor = rng.random(size=shape) + 1.5
+        res = _bracket_root(f, xl0, xr0, xmin=xmin, xmax=xmax, factor=factor,
+                            args=args, maxiter=maxiter)
+        refs = bracket_root_single(xl0, xr0, xmin, xmax, factor, p).ravel()
+
+        attrs = ['xl', 'xr', 'fl', 'fr', 'success', 'nfev', 'nit']
+        for attr in attrs:
+            ref_attr = [getattr(ref, attr) for ref in refs]
+            res_attr = getattr(res, attr)
+            assert_allclose(res_attr.ravel(), ref_attr)
+            assert_equal(res_attr.shape, shape)
+
+        assert np.issubdtype(res.success.dtype, np.bool_)
+        if shape:
+            assert np.all(res.success[1:-1])
+        assert np.issubdtype(res.status.dtype, np.integer)
+        assert np.issubdtype(res.nfev.dtype, np.integer)
+        assert np.issubdtype(res.nit.dtype, np.integer)
+        assert_equal(np.max(res.nit), f.f_evals - 2)
+        assert_array_less(res.xl, res.xr)
+        assert_allclose(res.fl, self.f(res.xl, *args))
+        assert_allclose(res.fr, self.f(res.xr, *args))
+
+    def test_flags(self):
+        # Test cases that should produce different status flags; show that all
+        # can be produced simultaneously.
+        def f(xs, js):
+            funcs = [lambda x: x - 1.5,
+                     lambda x: x - 1000,
+                     lambda x: x - 1000,
+                     lambda x: np.nan]
+
+            return [funcs[j](x) for x, j in zip(xs, js)]
+
+        args = (np.arange(4, dtype=np.int64),)
+        res = _bracket_root(f, xl0=[-1, -1, -1, -1], xr0=[1, 1, 1, 1],
+                            xmin=[-np.inf, -1, -np.inf, -np.inf],
+                            xmax=[np.inf, 1, np.inf, np.inf],
+                            args=args, maxiter=3)
+
+        ref_flags = np.array([eim._ECONVERGED,
+                              _ELIMITS,
+                              eim._ECONVERR,
+                              eim._EVALUEERR])
+        assert_equal(res.status, ref_flags)
+
+    @pytest.mark.parametrize("root", (0.622, [0.622, 0.623]))
+    @pytest.mark.parametrize('xmin', [-5, None])
+    @pytest.mark.parametrize('xmax', [5, None])
+    @pytest.mark.parametrize("dtype", (np.float16, np.float32, np.float64))
+    def test_dtype(self, root, xmin, xmax, dtype):
+        # Test that dtypes are preserved
+
+        xmin = xmin if xmin is None else dtype(xmin)
+        xmax = xmax if xmax is None else dtype(xmax)
+        root = dtype(root)
+        def f(x, root):
+            return ((x - root) ** 3).astype(dtype)
+
+        bracket = np.asarray([-0.01, 0.01], dtype=dtype)
+        res = _bracket_root(f, *bracket, xmin=xmin, xmax=xmax, args=(root,))
+        assert np.all(res.success)
+        assert res.xl.dtype == res.xr.dtype == dtype
+        assert res.fl.dtype == res.fr.dtype == dtype
+
+    def test_input_validation(self):
+        # Test input validation for appropriate error messages
+
+        message = '`func` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(None, -4, 4)
+
+        message = '...must be numeric and real.'
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4+1j, 4)
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 'hello')
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, xmin=np)
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, xmax=object())
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, factor=sum)
+
+        message = "All elements of `factor` must be greater than 1."
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, factor=0.5)
+
+        message = '`xmin <= xl0 < xr0 <= xmax` must be True'
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, 4, -4)
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, xmax=np.nan)
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, xmin=10)
+
+        message = "shape mismatch: objects cannot be broadcast"
+        # raised by `np.broadcast, but the traceback is readable IMO
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, [-2, -3], [3, 4, 5])
+        # Consider making this give a more readable error message
+        # with pytest.raises(ValueError, match=message):
+        #     _bracket_root(lambda x: [x[0], x[1], x[1]], [-3, -3], [5, 5])
+
+        message = '`maxiter` must be a non-negative integer.'
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, maxiter=1.5)
+        with pytest.raises(ValueError, match=message):
+            _bracket_root(lambda x: x, -4, 4, maxiter=-1)
+
+    def test_special_cases(self):
+        # Test edge cases and other special cases
+
+        # Test that integers are not passed to `f`
+        # (otherwise this would overflow)
+        def f(x):
+            assert np.issubdtype(x.dtype, np.floating)
+            return x ** 99 - 1
+
+        res = _bracket_root(f, -7, 5)
+        assert res.success
+
+        # Test maxiter = 0. Should do nothing to bracket.
+        def f(x):
+            return x - 10
+
+        bracket = (-3, 5)
+        res = _bracket_root(f, *bracket, maxiter=0)
+        assert res.xl, res.xr == bracket
+        assert res.nit == 0
+        assert res.nfev == 2
+        assert res.status == -2
+
+        # Test scalar `args` (not in tuple)
+        def f(x, c):
+            return c*x - 1
+
+        res = _bracket_root(f, -1, 1, args=3)
+        assert res.success
+        assert_allclose(res.fl, f(res.xl, 3))
+
+        # Test other edge cases
+
+        def f(x):
+            f.count += 1
+            return x
+
+        # 1. root lies within guess of bracket
+        f.count = 0
+        _bracket_root(f, -10, 20)
+        assert_equal(f.count, 2)
+
+        # 2. bracket endpoint hits root exactly
+        f.count = 0
+        res = _bracket_root(f, 5, 10, factor=2)
+        bracket = (res.xl, res.xr)
+        assert_equal(res.nfev, 4)
+        assert_allclose(bracket, (0, 5), atol=1e-15)
+
+        # 3. bracket limit hits root exactly
+        with np.errstate(over='ignore'):
+            res = _bracket_root(f, 5, 10, xmin=0)
+        bracket = (res.xl, res.xr)
+        assert_allclose(bracket[0], 0, atol=1e-15)
+        with np.errstate(over='ignore'):
+            res = _bracket_root(f, -10, -5, xmax=0)
+        bracket = (res.xl, res.xr)
+        assert_allclose(bracket[1], 0, atol=1e-15)
+
+        # 4. bracket not within min, max
+        with np.errstate(over='ignore'):
+            res = _bracket_root(f, 5, 10, xmin=1)
+        assert not res.success
+
+
+class TestBracketMinimum:
+    def init_f(self):
+        def f(x, a, b):
+            f.count += 1
+            return (x - a)**2 + b
+        f.count = 0
+        return f
+
+    def assert_valid_bracket(self, result):
+        assert np.all(
+            (result.xl < result.xm) & (result.xm < result.xr)
+        )
+        assert np.all(
+            (result.fl >= result.fm) & (result.fr > result.fm)
+            | (result.fl > result.fm) & (result.fr > result.fm)
+        )
+
+    def get_kwargs(
+            self, *, xl0=None, xr0=None, factor=None, xmin=None, xmax=None, args=()
+    ):
+        names = ("xl0", "xr0", "xmin", "xmax", "factor", "args")
+        return {
+            name: val for name, val in zip(names, (xl0, xr0, xmin, xmax, factor, args))
+            if isinstance(val, np.ndarray) or np.isscalar(val)
+            or val not in [None, ()]
+        }
+
+    @pytest.mark.parametrize(
+        "seed",
+        (
+            307448016549685229886351382450158984917,
+            11650702770735516532954347931959000479,
+            113767103358505514764278732330028568336,
+        )
+    )
+    @pytest.mark.parametrize("use_xmin", (False, True))
+    @pytest.mark.parametrize("other_side", (False, True))
+    def test_nfev_expected(self, seed, use_xmin, other_side):
+        rng = np.random.default_rng(seed)
+        args = (0, 0)  # f(x) = x^2 with minimum at 0
+        # xl0, xm0, xr0 are chosen such that the initial bracket is to
+        # the right of the minimum, and the bracket will expand
+        # downhill towards zero.
+        xl0, d1, d2, factor = rng.random(size=4) * [1e5, 10, 10, 5]
+        xm0 = xl0 + d1
+        xr0 = xm0 + d2
+        # Factor should be greater than one.
+        factor += 1
+
+        if use_xmin:
+            xmin = -rng.random() * 5
+            n = int(np.ceil(np.log(-(xl0 - xmin) / xmin) / np.log(factor)))
+            lower = xmin + (xl0 - xmin)*factor**-n
+            middle = xmin + (xl0 - xmin)*factor**-(n-1)
+            upper = xmin + (xl0 - xmin)*factor**-(n-2) if n > 1 else xm0
+            # It may be the case the lower is below the minimum, but we still
+            # don't have a valid bracket.
+            if middle**2 > lower**2:
+                n += 1
+                lower, middle, upper = (
+                    xmin + (xl0 - xmin)*factor**-n, lower, middle
+                )
+        else:
+            xmin = None
+            n = int(np.ceil(np.log(xl0 / d1) / np.log(factor)))
+            lower = xl0 - d1*factor**n
+            middle = xl0 - d1*factor**(n-1) if n > 1 else xl0
+            upper = xl0 - d1*factor**(n-2) if n > 1 else xm0
+            # It may be the case the lower is below the minimum, but we still
+            # don't have a valid bracket.
+            if middle**2 > lower**2:
+                n += 1
+                lower, middle, upper = (
+                    xl0 - d1*factor**n, lower, middle
+                )
+        f = self.init_f()
+
+        xmax = None
+        if other_side:
+            xl0, xm0, xr0 = -xr0, -xm0, -xl0
+            xmin, xmax = None, -xmin if xmin is not None else None
+            lower, middle, upper = -upper, -middle, -lower
+
+        kwargs = self.get_kwargs(
+            xl0=xl0, xr0=xr0, xmin=xmin, xmax=xmax, factor=factor, args=args
+        )
+        result = _bracket_minimum(f, xm0, **kwargs)
+
+        # Check that `nfev` and `nit` have the correct relationship
+        assert result.nfev == result.nit + 3
+        # Check that `nfev` reports the correct number of function evaluations.
+        assert result.nfev == f.count
+        # Check that the number of iterations matches the theoretical value.
+        assert result.nit == n
+
+        # Compare reported bracket to theoretical bracket and reported function
+        # values to function evaluated at bracket.
+        bracket = np.asarray([result.xl, result.xm, result.xr])
+        assert_allclose(bracket, (lower, middle, upper))
+        f_bracket = np.asarray([result.fl, result.fm, result.fr])
+        assert_allclose(f_bracket, f(bracket, *args))
+
+        self.assert_valid_bracket(result)
+        assert result.status == 0
+        assert result.success
+
+    def test_flags(self):
+        # Test cases that should produce different status flags; show that all
+        # can be produced simultaneously
+        def f(xs, js):
+            funcs = [lambda x: (x - 1.5)**2,
+                     lambda x: x,
+                     lambda x: x,
+                     lambda x: np.nan]
+            return [funcs[j](x) for x, j in zip(xs, js)]
+
+        args = (np.arange(4, dtype=np.int64),)
+        xl0, xm0, xr0 = np.full(4, -1.0), np.full(4, 0.0), np.full(4, 1.0)
+        result = _bracket_minimum(f, xm0, xl0=xl0, xr0=xr0,
+                                  xmin=[-np.inf, -1.0, -np.inf, -np.inf],
+                                  args=args, maxiter=3)
+
+        reference_flags = np.array([eim._ECONVERGED, _ELIMITS,
+                                    eim._ECONVERR, eim._EVALUEERR])
+        assert_equal(result.status, reference_flags)
+
+    @pytest.mark.parametrize("minimum", (0.622, [0.622, 0.623]))
+    @pytest.mark.parametrize("dtype", (np.float16, np.float32, np.float64))
+    @pytest.mark.parametrize("xmin", [-5, None])
+    @pytest.mark.parametrize("xmax", [5, None])
+    def test_dtypes(self, minimum, xmin, xmax, dtype):
+        xmin = xmin if xmin is None else dtype(xmin)
+        xmax = xmax if xmax is None else dtype(xmax)
+        minimum = dtype(minimum)
+
+        def f(x, minimum):
+            return ((x - minimum)**2).astype(dtype)
+
+        xl0, xm0, xr0 = np.array([-0.01, 0.0, 0.01], dtype=dtype)
+        result = _bracket_minimum(
+            f, xm0, xl0=xl0, xr0=xr0, xmin=xmin, xmax=xmax, args=(minimum, )
+        )
+        assert np.all(result.success)
+        assert result.xl.dtype == result.xm.dtype == result.xr.dtype == dtype
+        assert result.fl.dtype == result.fm.dtype == result.fr.dtype == dtype
+
+    def test_input_validation(self):
+        # Test input validation for appropriate error messages
+
+        message = '`func` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(None, -4, xl0=4)
+
+        message = '...must be numeric and real.'
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, 4+1j)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xl0='hello')
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xmin=np)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xmax=object())
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, factor=sum)
+
+        message = "All elements of `factor` must be greater than 1."
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x, -4, factor=0.5)
+
+        message = '`xmin <= xl0 < xm0 < xr0 <= xmax` must be True'
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, 4, xl0=6)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xr0=-6)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xl0=-3, xr0=-2)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xl0=-6, xr0=-5)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xl0=-np.nan)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xr0=np.nan)
+
+        message = "shape mismatch: objects cannot be broadcast"
+        # raised by `np.broadcast, but the traceback is readable IMO
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, [-2, -3], xl0=[-3, -4, -5])
+
+        message = '`maxiter` must be a non-negative integer.'
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xr0=4, maxiter=1.5)
+        with pytest.raises(ValueError, match=message):
+            _bracket_minimum(lambda x: x**2, -4, xr0=4, maxiter=-1)
+
+    @pytest.mark.parametrize("xl0", [0.0, None])
+    @pytest.mark.parametrize("xm0", (0.05, 0.1, 0.15))
+    @pytest.mark.parametrize("xr0", (0.2, 0.4, 0.6, None))
+    # Minimum is ``a`` for each tuple ``(a, b)`` below. Tests cases where minimum
+    # is within, or at varying disances to the left or right of the initial
+    # bracket.
+    @pytest.mark.parametrize(
+        "args",
+        (
+            (1.2, 0), (-0.5, 0), (0.1, 0), (0.2, 0), (3.6, 0), (21.4, 0),
+            (121.6, 0), (5764.1, 0), (-6.4, 0), (-12.9, 0), (-146.2, 0)
+        )
+    )
+    def test_scalar_no_limits(self, xl0, xm0, xr0, args):
+        f = self.init_f()
+        kwargs = self.get_kwargs(xl0=xl0, xr0=xr0, args=args)
+        result = _bracket_minimum(f, xm0, **kwargs)
+        self.assert_valid_bracket(result)
+        assert result.status == 0
+        assert result.success
+        assert result.nfev == f.count
+
+    @pytest.mark.parametrize(
+        # xmin is set at 0.0 in all cases.
+        "xl0,xm0,xr0,xmin",
+        (
+            # Initial bracket at varying distances from the xmin.
+            (0.5, 0.75, 1.0, 0.0),
+            (1.0, 2.5, 4.0, 0.0),
+            (2.0, 4.0, 6.0, 0.0),
+            (12.0, 16.0, 20.0, 0.0),
+            # Test default initial left endpoint selection. It should not
+            # be below xmin.
+            (None, 0.75, 1.0, 0.0),
+            (None, 2.5, 4.0, 0.0),
+            (None, 4.0, 6.0, 0.0),
+            (None, 16.0, 20.0, 0.0),
+        )
+    )
+    @pytest.mark.parametrize(
+        "args", (
+            (0.0, 0.0), # Minimum is directly at xmin.
+            (1e-300, 0.0), # Minimum is extremely close to xmin.
+            (1e-20, 0.0), # Minimum is very close to xmin.
+            # Minimum at varying distances from xmin.
+            (0.1, 0.0),
+            (0.2, 0.0),
+            (0.4, 0.0)
+        )
+    )
+    def test_scalar_with_limit_left(self, xl0, xm0, xr0, xmin, args):
+        f = self.init_f()
+        kwargs = self.get_kwargs(xl0=xl0, xr0=xr0, xmin=xmin, args=args)
+        result = _bracket_minimum(f, xm0, **kwargs)
+        self.assert_valid_bracket(result)
+        assert result.status == 0
+        assert result.success
+        assert result.nfev == f.count
+
+    @pytest.mark.parametrize(
+        #xmax is set to 1.0 in all cases.
+        "xl0,xm0,xr0,xmax",
+        (
+            # Bracket at varying distances from xmax.
+            (0.2, 0.3, 0.4, 1.0),
+            (0.05, 0.075, 0.1, 1.0),
+            (-0.2, -0.1, 0.0, 1.0),
+            (-21.2, -17.7, -14.2, 1.0),
+            # Test default right endpoint selection. It should not exceed xmax.
+            (0.2, 0.3, None, 1.0),
+            (0.05, 0.075, None, 1.0),
+            (-0.2, -0.1, None, 1.0),
+            (-21.2, -17.7, None, 1.0),
+        )
+    )
+    @pytest.mark.parametrize(
+        "args", (
+            (0.9999999999999999, 0.0), # Minimum very close to xmax.
+            # Minimum at varying distances from xmax.
+            (0.9, 0.0),
+            (0.7, 0.0),
+            (0.5, 0.0)
+        )
+    )
+    def test_scalar_with_limit_right(self, xl0, xm0, xr0, xmax, args):
+        f = self.init_f()
+        kwargs = self.get_kwargs(xl0=xl0, xr0=xr0, xmax=xmax, args=args)
+        result = _bracket_minimum(f, xm0, **kwargs)
+        self.assert_valid_bracket(result)
+        assert result.status == 0
+        assert result.success
+        assert result.nfev == f.count
+
+    @pytest.mark.parametrize(
+        "xl0,xm0,xr0,xmin,xmax,args",
+        (
+            (   # Case 1:
+                # Initial bracket.
+                0.2, 
+                0.3,
+                0.4,
+                # Function slopes down to the right from the bracket to a minimum
+                # at 1.0. xmax is also at 1.0
+                None, 
+                1.0,
+                (1.0, 0.0)
+            ),
+            (   # Case 2:
+                # Initial bracket.
+                1.4,
+                1.95,
+                2.5,
+                # Function slopes down to the left from the bracket to a minimum at
+                # 0.3 with xmin set to 0.3.
+                0.3,
+                None,
+                (0.3, 0.0)
+            ),
+            (
+                # Case 3:
+                # Initial bracket.
+                2.6,
+                3.25,
+                3.9,
+                # Function slopes down and to the right to a minimum at 99.4 with xmax
+                # at 99.4. Tests case where minimum is at xmax relatively further from
+                # the bracket.
+                None,
+                99.4,
+                (99.4, 0)
+            ),
+            (
+                # Case 4:
+                # Initial bracket.
+                4,
+                4.5,
+                5,
+                # Function slopes down and to the left away from the bracket with a
+                # minimum at -26.3 with xmin set to -26.3. Tests case where minimum is
+                # at xmin relatively far from the bracket.
+                -26.3,
+                None,
+                (-26.3, 0)
+            ),
+            (
+                # Case 5:
+                # Similar to Case 1 above, but tests default values of xl0 and xr0.
+                None,
+                0.3,
+                None,
+                None,
+                1.0,
+                (1.0, 0.0)
+            ),
+            (   # Case 6:
+                # Similar to Case 2 above, but tests default values of xl0 and xr0.
+                None,
+                1.95,
+                None,
+                0.3,
+                None,
+                (0.3, 0.0)
+            ),
+            (
+                # Case 7:
+                # Similar to Case 3 above, but tests default values of xl0 and xr0.
+                None,
+                3.25,
+                None,
+                None,
+                99.4,
+                (99.4, 0)
+            ),
+            (
+                # Case 8:
+                # Similar to Case 4 above, but tests default values of xl0 and xr0.
+                None,
+                4.5,
+                None,
+                -26.3,
+                None,
+                (-26.3, 0)
+            ),
+        )
+    )
+    def test_minimum_at_boundary_point(self, xl0, xm0, xr0, xmin, xmax, args):
+        f = self.init_f()
+        kwargs = self.get_kwargs(xr0=xr0, xmin=xmin, xmax=xmax, args=args)
+        result = _bracket_minimum(f, xm0, **kwargs)
+        assert result.status == -1
+        assert args[0] in (result.xl, result.xr)
+        assert result.nfev == f.count
+
+    @pytest.mark.parametrize('shape', [tuple(), (12, ), (3, 4), (3, 2, 2)])
+    def test_vectorization(self, shape):
+        # Test for correct functionality, output shapes, and dtypes for
+        # various input shapes.
+        a = np.linspace(-0.05, 1.05, 12).reshape(shape) if shape else 0.6
+        args = (a, 0.0)
+        maxiter = 10
+
+        @np.vectorize
+        def bracket_minimum_single(xm0, xl0, xr0, xmin, xmax, factor, a):
+            return _bracket_minimum(self.init_f(), xm0, xl0=xl0, xr0=xr0, xmin=xmin,
+                                    xmax=xmax, factor=factor, maxiter=maxiter,
+                                    args=(a, 0.0))
+
+        f = self.init_f()
+
+        rng = np.random.default_rng(2348234)
+        xl0 = -rng.random(size=shape)
+        xr0 = rng.random(size=shape)
+        xm0 = xl0 + rng.random(size=shape) * (xr0 - xl0)
+        xmin, xmax = 1e3*xl0, 1e3*xr0
+        if shape:  # make some elements un
+            i = rng.random(size=shape) > 0.5
+            xmin[i], xmax[i] = -np.inf, np.inf
+        factor = rng.random(size=shape) + 1.5
+        res = _bracket_minimum(f, xm0, xl0=xl0, xr0=xr0, xmin=xmin, xmax=xmax,
+                               factor=factor, args=args, maxiter=maxiter)
+        refs = bracket_minimum_single(xm0, xl0, xr0, xmin, xmax, factor, a).ravel()
+
+        attrs = ['xl', 'xm', 'xr', 'fl', 'fm', 'fr', 'success', 'nfev', 'nit']
+        for attr in attrs:
+            ref_attr = [getattr(ref, attr) for ref in refs]
+            res_attr = getattr(res, attr)
+            assert_allclose(res_attr.ravel(), ref_attr)
+            assert_equal(res_attr.shape, shape)
+
+        assert np.issubdtype(res.success.dtype, np.bool_)
+        if shape:
+            assert np.all(res.success[1:-1])
+        assert np.issubdtype(res.status.dtype, np.integer)
+        assert np.issubdtype(res.nfev.dtype, np.integer)
+        assert np.issubdtype(res.nit.dtype, np.integer)
+        assert_equal(np.max(res.nit), f.count - 3)
+        self.assert_valid_bracket(res)
+        assert_allclose(res.fl, f(res.xl, *args))
+        assert_allclose(res.fm, f(res.xm, *args))
+        assert_allclose(res.fr, f(res.xr, *args))
+
+    def test_special_cases(self):
+        # Test edge cases and other special cases.
+
+        # Test that integers are not passed to `f`
+        # (otherwise this would overflow)
+        def f(x):
+            assert np.issubdtype(x.dtype, np.floating)
+            return x ** 98 - 1
+
+        result = _bracket_minimum(f, -7, xr0=5)
+        assert result.success
+
+        # Test maxiter = 0. Should do nothing to bracket.
+        def f(x):
+            return x**2 - 10
+
+        xl0, xm0, xr0 = -3, -1, 2
+        result = _bracket_minimum(f, xm0, xl0=xl0, xr0=xr0, maxiter=0)
+        assert_equal([result.xl, result.xm, result.xr], [xl0, xm0, xr0])
+
+        # Test scalar `args` (not in tuple)
+        def f(x, c):
+            return c*x**2 - 1
+
+        result = _bracket_minimum(f, -1, args=3)
+        assert result.success
+        assert_allclose(result.fl, f(result.xl, 3))
+
+        # Initial bracket is valid.
+        f = self.init_f()
+        xl0, xm0, xr0 = [-1.0, -0.2, 1.0]
+        args = (0, 0)
+        result = _bracket_minimum(f, xm0, xl0=xl0, xr0=xr0, args=args)
+        assert f.count == 3
+
+        assert_equal(
+            [result.xl, result.xm, result.xr],
+            [xl0, xm0, xr0],
+        )
+        assert_equal(
+            [result.fl, result.fm, result.fr],
+            [f(xl0, *args), f(xm0, *args), f(xr0, *args)],
+        )

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_chandrupatla.py

@@ -0,0 +1,827 @@
+import pytest
+import numpy as np
+from numpy.testing import assert_allclose, assert_equal, assert_array_less
+
+from scipy import stats
+import scipy._lib._elementwise_iterative_method as eim
+
+from scipy.optimize._chandrupatla import (_chandrupatla_minimize,
+                                          _chandrupatla as _chandrupatla_root)
+from scipy.optimize._tstutils import _CHANDRUPATLA_TESTS
+
+from itertools import permutations
+from .test_zeros import TestScalarRootFinders
+
+def f1(x):
+    return 100*(1 - x**3.)**2 + (1-x**2.) + 2*(1-x)**2.
+
+
+def f2(x):
+    return 5 + (x - 2.)**6
+
+
+def f3(x):
+    return np.exp(x) - 5*x
+
+
+def f4(x):
+    return x**5. - 5*x**3. - 20.*x + 5.
+
+
+def f5(x):
+    return 8*x**3 - 2*x**2 - 7*x + 3
+
+
+def _bracket_minimum(func, x1, x2):
+    phi = 1.61803398875
+    maxiter = 100
+    f1 = func(x1)
+    f2 = func(x2)
+    step = x2 - x1
+    x1, x2, f1, f2, step = ((x2, x1, f2, f1, -step) if f2 > f1
+                            else (x1, x2, f1, f2, step))
+
+    for i in range(maxiter):
+        step *= phi
+        x3 = x2 + step
+        f3 = func(x3)
+        if f3 < f2:
+            x1, x2, f1, f2 = x2, x3, f2, f3
+        else:
+            break
+    return x1, x2, x3, f1, f2, f3
+
+
+cases = [
+    (f1, -1, 11),
+    (f1, -2, 13),
+    (f1, -4, 13),
+    (f1, -8, 15),
+    (f1, -16, 16),
+    (f1, -32, 19),
+    (f1, -64, 20),
+    (f1, -128, 21),
+    (f1, -256, 21),
+    (f1, -512, 19),
+    (f1, -1024, 24),
+    (f2, -1, 8),
+    (f2, -2, 6),
+    (f2, -4, 6),
+    (f2, -8, 7),
+    (f2, -16, 8),
+    (f2, -32, 8),
+    (f2, -64, 9),
+    (f2, -128, 11),
+    (f2, -256, 13),
+    (f2, -512, 12),
+    (f2, -1024, 13),
+    (f3, -1, 11),
+    (f3, -2, 11),
+    (f3, -4, 11),
+    (f3, -8, 10),
+    (f3, -16, 14),
+    (f3, -32, 12),
+    (f3, -64, 15),
+    (f3, -128, 18),
+    (f3, -256, 18),
+    (f3, -512, 19),
+    (f3, -1024, 19),
+    (f4, -0.05, 9),
+    (f4, -0.10, 11),
+    (f4, -0.15, 11),
+    (f4, -0.20, 11),
+    (f4, -0.25, 11),
+    (f4, -0.30, 9),
+    (f4, -0.35, 9),
+    (f4, -0.40, 9),
+    (f4, -0.45, 10),
+    (f4, -0.50, 10),
+    (f4, -0.55, 10),
+    (f5, -0.05, 6),
+    (f5, -0.10, 7),
+    (f5, -0.15, 8),
+    (f5, -0.20, 10),
+    (f5, -0.25, 9),
+    (f5, -0.30, 8),
+    (f5, -0.35, 7),
+    (f5, -0.40, 7),
+    (f5, -0.45, 9),
+    (f5, -0.50, 9),
+    (f5, -0.55, 8)
+]
+
+
+class TestChandrupatlaMinimize:
+
+    def f(self, x, loc):
+        dist = stats.norm()
+        return -dist.pdf(x - loc)
+
+    @pytest.mark.parametrize('loc', [0.6, np.linspace(-1.05, 1.05, 10)])
+    def test_basic(self, loc):
+        # Find mode of normal distribution. Compare mode against location
+        # parameter and value of pdf at mode against expected pdf.
+        res = _chandrupatla_minimize(self.f, -5, 0, 5, args=(loc,))
+        ref = loc
+        np.testing.assert_allclose(res.x, ref, rtol=1e-6)
+        np.testing.assert_allclose(res.fun, -stats.norm.pdf(0), atol=0, rtol=0)
+        assert res.x.shape == np.shape(ref)
+
+    @pytest.mark.parametrize('shape', [tuple(), (12,), (3, 4), (3, 2, 2)])
+    def test_vectorization(self, shape):
+        # Test for correct functionality, output shapes, and dtypes for various
+        # input shapes.
+        loc = np.linspace(-0.05, 1.05, 12).reshape(shape) if shape else 0.6
+        args = (loc,)
+
+        @np.vectorize
+        def chandrupatla_single(loc_single):
+            return _chandrupatla_minimize(self.f, -5, 0, 5, args=(loc_single,))
+
+        def f(*args, **kwargs):
+            f.f_evals += 1
+            return self.f(*args, **kwargs)
+        f.f_evals = 0
+
+        res = _chandrupatla_minimize(f, -5, 0, 5, args=args)
+        refs = chandrupatla_single(loc).ravel()
+
+        ref_x = [ref.x for ref in refs]
+        assert_allclose(res.x.ravel(), ref_x)
+        assert_equal(res.x.shape, shape)
+
+        ref_fun = [ref.fun for ref in refs]
+        assert_allclose(res.fun.ravel(), ref_fun)
+        assert_equal(res.fun.shape, shape)
+        assert_equal(res.fun, self.f(res.x, *args))
+
+        ref_success = [ref.success for ref in refs]
+        assert_equal(res.success.ravel(), ref_success)
+        assert_equal(res.success.shape, shape)
+        assert np.issubdtype(res.success.dtype, np.bool_)
+
+        ref_flag = [ref.status for ref in refs]
+        assert_equal(res.status.ravel(), ref_flag)
+        assert_equal(res.status.shape, shape)
+        assert np.issubdtype(res.status.dtype, np.integer)
+
+        ref_nfev = [ref.nfev for ref in refs]
+        assert_equal(res.nfev.ravel(), ref_nfev)
+        assert_equal(np.max(res.nfev), f.f_evals)
+        assert_equal(res.nfev.shape, res.fun.shape)
+        assert np.issubdtype(res.nfev.dtype, np.integer)
+
+        ref_nit = [ref.nit for ref in refs]
+        assert_equal(res.nit.ravel(), ref_nit)
+        assert_equal(np.max(res.nit), f.f_evals-3)
+        assert_equal(res.nit.shape, res.fun.shape)
+        assert np.issubdtype(res.nit.dtype, np.integer)
+
+        ref_xl = [ref.xl for ref in refs]
+        assert_allclose(res.xl.ravel(), ref_xl)
+        assert_equal(res.xl.shape, shape)
+
+        ref_xm = [ref.xm for ref in refs]
+        assert_allclose(res.xm.ravel(), ref_xm)
+        assert_equal(res.xm.shape, shape)
+
+        ref_xr = [ref.xr for ref in refs]
+        assert_allclose(res.xr.ravel(), ref_xr)
+        assert_equal(res.xr.shape, shape)
+
+        ref_fl = [ref.fl for ref in refs]
+        assert_allclose(res.fl.ravel(), ref_fl)
+        assert_equal(res.fl.shape, shape)
+        assert_allclose(res.fl, self.f(res.xl, *args))
+
+        ref_fm = [ref.fm for ref in refs]
+        assert_allclose(res.fm.ravel(), ref_fm)
+        assert_equal(res.fm.shape, shape)
+        assert_allclose(res.fm, self.f(res.xm, *args))
+
+        ref_fr = [ref.fr for ref in refs]
+        assert_allclose(res.fr.ravel(), ref_fr)
+        assert_equal(res.fr.shape, shape)
+        assert_allclose(res.fr, self.f(res.xr, *args))
+
+    def test_flags(self):
+        # Test cases that should produce different status flags; show that all
+        # can be produced simultaneously.
+        def f(xs, js):
+            funcs = [lambda x: (x - 2.5) ** 2,
+                     lambda x: x - 10,
+                     lambda x: (x - 2.5) ** 4,
+                     lambda x: np.nan]
+
+            return [funcs[j](x) for x, j in zip(xs, js)]
+
+        args = (np.arange(4, dtype=np.int64),)
+
+        res = _chandrupatla_minimize(f, [0]*4, [2]*4, [np.pi]*4, args=args,
+                                     maxiter=10)
+
+        ref_flags = np.array([eim._ECONVERGED,
+                              eim._ESIGNERR,
+                              eim._ECONVERR,
+                              eim._EVALUEERR])
+        assert_equal(res.status, ref_flags)
+
+    def test_convergence(self):
+        # Test that the convergence tolerances behave as expected
+        rng = np.random.default_rng(2585255913088665241)
+        p = rng.random(size=3)
+        bracket = (-5, 0, 5)
+        args = (p,)
+        kwargs0 = dict(args=args, xatol=0, xrtol=0, fatol=0, frtol=0)
+
+        kwargs = kwargs0.copy()
+        kwargs['xatol'] = 1e-3
+        res1 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        j1 = abs(res1.xr - res1.xl)
+        assert_array_less(j1, 4*kwargs['xatol'])
+        kwargs['xatol'] = 1e-6
+        res2 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        j2 = abs(res2.xr - res2.xl)
+        assert_array_less(j2, 4*kwargs['xatol'])
+        assert_array_less(j2, j1)
+
+        kwargs = kwargs0.copy()
+        kwargs['xrtol'] = 1e-3
+        res1 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        j1 = abs(res1.xr - res1.xl)
+        assert_array_less(j1, 4*kwargs['xrtol']*abs(res1.x))
+        kwargs['xrtol'] = 1e-6
+        res2 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        j2 = abs(res2.xr - res2.xl)
+        assert_array_less(j2, 4*kwargs['xrtol']*abs(res2.x))
+        assert_array_less(j2, j1)
+
+        kwargs = kwargs0.copy()
+        kwargs['fatol'] = 1e-3
+        res1 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        h1 = abs(res1.fl - 2 * res1.fm + res1.fr)
+        assert_array_less(h1, 2*kwargs['fatol'])
+        kwargs['fatol'] = 1e-6
+        res2 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        h2 = abs(res2.fl - 2 * res2.fm + res2.fr)
+        assert_array_less(h2, 2*kwargs['fatol'])
+        assert_array_less(h2, h1)
+
+        kwargs = kwargs0.copy()
+        kwargs['frtol'] = 1e-3
+        res1 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        h1 = abs(res1.fl - 2 * res1.fm + res1.fr)
+        assert_array_less(h1, 2*kwargs['frtol']*abs(res1.fun))
+        kwargs['frtol'] = 1e-6
+        res2 = _chandrupatla_minimize(self.f, *bracket, **kwargs)
+        h2 = abs(res2.fl - 2 * res2.fm + res2.fr)
+        assert_array_less(h2, 2*kwargs['frtol']*abs(res2.fun))
+        assert_array_less(h2, h1)
+
+    def test_maxiter_callback(self):
+        # Test behavior of `maxiter` parameter and `callback` interface
+        loc = 0.612814
+        bracket = (-5, 0, 5)
+        maxiter = 5
+
+        res = _chandrupatla_minimize(self.f, *bracket, args=(loc,),
+                                     maxiter=maxiter)
+        assert not np.any(res.success)
+        assert np.all(res.nfev == maxiter+3)
+        assert np.all(res.nit == maxiter)
+
+        def callback(res):
+            callback.iter += 1
+            callback.res = res
+            assert hasattr(res, 'x')
+            if callback.iter == 0:
+                # callback is called once with initial bracket
+                assert (res.xl, res.xm, res.xr) == bracket
+            else:
+                changed_xr = (res.xl == callback.xl) & (res.xr != callback.xr)
+                changed_xl = (res.xl != callback.xl) & (res.xr == callback.xr)
+                assert np.all(changed_xr | changed_xl)
+
+            callback.xl = res.xl
+            callback.xr = res.xr
+            assert res.status == eim._EINPROGRESS
+            assert_equal(self.f(res.xl, loc), res.fl)
+            assert_equal(self.f(res.xm, loc), res.fm)
+            assert_equal(self.f(res.xr, loc), res.fr)
+            assert_equal(self.f(res.x, loc), res.fun)
+            if callback.iter == maxiter:
+                raise StopIteration
+
+        callback.xl = np.nan
+        callback.xr = np.nan
+        callback.iter = -1  # callback called once before first iteration
+        callback.res = None
+
+        res2 = _chandrupatla_minimize(self.f, *bracket, args=(loc,),
+                                      callback=callback)
+
+        # terminating with callback is identical to terminating due to maxiter
+        # (except for `status`)
+        for key in res.keys():
+            if key == 'status':
+                assert res[key] == eim._ECONVERR
+                assert callback.res[key] == eim._EINPROGRESS
+                assert res2[key] == eim._ECALLBACK
+            else:
+                assert res2[key] == callback.res[key] == res[key]
+
+    @pytest.mark.parametrize('case', cases)
+    def test_nit_expected(self, case):
+        # Test that `_chandrupatla` implements Chandrupatla's algorithm:
+        # in all 55 test cases, the number of iterations performed
+        # matches the number reported in the original paper.
+        func, x1, nit = case
+
+        # Find bracket using the algorithm in the paper
+        step = 0.2
+        x2 = x1 + step
+        x1, x2, x3, f1, f2, f3 = _bracket_minimum(func, x1, x2)
+
+        # Use tolerances from original paper
+        xatol = 0.0001
+        fatol = 0.000001
+        xrtol = 1e-16
+        frtol = 1e-16
+
+        res = _chandrupatla_minimize(func, x1, x2, x3, xatol=xatol,
+                                     fatol=fatol, xrtol=xrtol, frtol=frtol)
+        assert_equal(res.nit, nit)
+
+    @pytest.mark.parametrize("loc", (0.65, [0.65, 0.7]))
+    @pytest.mark.parametrize("dtype", (np.float16, np.float32, np.float64))
+    def test_dtype(self, loc, dtype):
+        # Test that dtypes are preserved
+
+        loc = dtype(loc)
+
+        def f(x, loc):
+            assert x.dtype == dtype
+            return ((x - loc) ** 2).astype(dtype)
+
+        res = _chandrupatla_minimize(f, dtype(-3), dtype(1), dtype(5),
+                                     args=(loc,))
+        assert res.x.dtype == dtype
+        assert_allclose(res.x, loc, rtol=np.sqrt(np.finfo(dtype).eps))
+
+    def test_input_validation(self):
+        # Test input validation for appropriate error messages
+
+        message = '`func` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(None, -4, 0, 4)
+
+        message = 'Abscissae and function output must be real numbers.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4+1j, 0, 4)
+
+        message = "shape mismatch: objects cannot be broadcast"
+        # raised by `np.broadcast, but the traceback is readable IMO
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, [-2, -3], [0, 0], [3, 4, 5])
+
+        message = "The shape of the array returned by `func` must be the same"
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: [x[0], x[1], x[1]], [-3, -3],
+                                   [0, 0], [5, 5])
+
+        message = 'Tolerances must be non-negative scalars.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, xatol=-1)
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, xrtol=np.nan)
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, fatol='ekki')
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, frtol=np.nan)
+
+        message = '`maxiter` must be a non-negative integer.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, maxiter=1.5)
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, maxiter=-1)
+
+        message = '`callback` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_minimize(lambda x: x, -4, 0, 4, callback='shrubbery')
+
+    def test_bracket_order(self):
+        # Confirm that order of points in bracket doesn't matter
+        loc = np.linspace(-1, 1, 6)[:, np.newaxis]
+        brackets = np.array(list(permutations([-5, 0, 5]))).T
+        res = _chandrupatla_minimize(self.f, *brackets, args=(loc,))
+        assert np.all(np.isclose(res.x, loc) | (res.fun == self.f(loc, loc)))
+        ref = res.x[:, 0]  # all columns should be the same
+        assert_allclose(*np.broadcast_arrays(res.x.T, ref), rtol=1e-15)
+
+    def test_special_cases(self):
+        # Test edge cases and other special cases
+
+        # Test that integers are not passed to `f`
+        # (otherwise this would overflow)
+        def f(x):
+            assert np.issubdtype(x.dtype, np.floating)
+            return (x-1) ** 100
+
+        with np.errstate(invalid='ignore'):
+            res = _chandrupatla_minimize(f, -7, 0, 8, fatol=0, frtol=0)
+        assert res.success
+        assert_allclose(res.x, 1, rtol=1e-3)
+        assert_equal(res.fun, 0)
+
+        # Test that if all elements of bracket equal minimizer, algorithm
+        # reports convergence
+        def f(x):
+            return (x-1)**2
+
+        res = _chandrupatla_minimize(f, 1, 1, 1)
+        assert res.success
+        assert_equal(res.x, 1)
+
+        # Test maxiter = 0. Should do nothing to bracket.
+        def f(x):
+            return (x-1)**2
+
+        bracket = (-3, 1.1, 5)
+        res = _chandrupatla_minimize(f, *bracket, maxiter=0)
+        assert res.xl, res.xr == bracket
+        assert res.nit == 0
+        assert res.nfev == 3
+        assert res.status == -2
+        assert res.x == 1.1  # best so far
+
+        # Test scalar `args` (not in tuple)
+        def f(x, c):
+            return (x-c)**2 - 1
+
+        res = _chandrupatla_minimize(f, -1, 0, 1, args=1/3)
+        assert_allclose(res.x, 1/3)
+
+        # Test zero tolerances
+        # TODO: fatol/frtol = 0?
+        def f(x):
+            return -np.sin(x)
+
+        res = _chandrupatla_minimize(f, 0, 1, np.pi, xatol=0, xrtol=0,
+                                     fatol=0, frtol=0)
+        assert res.success
+        # found a minimum exactly (according to floating point arithmetic)
+        assert res.xl < res.xm < res.xr
+        assert f(res.xl) == f(res.xm) == f(res.xr)
+
+
+class TestChandrupatla(TestScalarRootFinders):
+
+    def f(self, q, p):
+        return stats.norm.cdf(q) - p
+
+    @pytest.mark.parametrize('p', [0.6, np.linspace(-0.05, 1.05, 10)])
+    def test_basic(self, p):
+        # Invert distribution CDF and compare against distrtibution `ppf`
+        res = _chandrupatla_root(self.f, -5, 5, args=(p,))
+        ref = stats.norm().ppf(p)
+        np.testing.assert_allclose(res.x, ref)
+        assert res.x.shape == ref.shape
+
+    @pytest.mark.parametrize('shape', [tuple(), (12,), (3, 4), (3, 2, 2)])
+    def test_vectorization(self, shape):
+        # Test for correct functionality, output shapes, and dtypes for various
+        # input shapes.
+        p = np.linspace(-0.05, 1.05, 12).reshape(shape) if shape else 0.6
+        args = (p,)
+
+        @np.vectorize
+        def chandrupatla_single(p):
+            return _chandrupatla_root(self.f, -5, 5, args=(p,))
+
+        def f(*args, **kwargs):
+            f.f_evals += 1
+            return self.f(*args, **kwargs)
+        f.f_evals = 0
+
+        res = _chandrupatla_root(f, -5, 5, args=args)
+        refs = chandrupatla_single(p).ravel()
+
+        ref_x = [ref.x for ref in refs]
+        assert_allclose(res.x.ravel(), ref_x)
+        assert_equal(res.x.shape, shape)
+
+        ref_fun = [ref.fun for ref in refs]
+        assert_allclose(res.fun.ravel(), ref_fun)
+        assert_equal(res.fun.shape, shape)
+        assert_equal(res.fun, self.f(res.x, *args))
+
+        ref_success = [ref.success for ref in refs]
+        assert_equal(res.success.ravel(), ref_success)
+        assert_equal(res.success.shape, shape)
+        assert np.issubdtype(res.success.dtype, np.bool_)
+
+        ref_flag = [ref.status for ref in refs]
+        assert_equal(res.status.ravel(), ref_flag)
+        assert_equal(res.status.shape, shape)
+        assert np.issubdtype(res.status.dtype, np.integer)
+
+        ref_nfev = [ref.nfev for ref in refs]
+        assert_equal(res.nfev.ravel(), ref_nfev)
+        assert_equal(np.max(res.nfev), f.f_evals)
+        assert_equal(res.nfev.shape, res.fun.shape)
+        assert np.issubdtype(res.nfev.dtype, np.integer)
+
+        ref_nit = [ref.nit for ref in refs]
+        assert_equal(res.nit.ravel(), ref_nit)
+        assert_equal(np.max(res.nit), f.f_evals-2)
+        assert_equal(res.nit.shape, res.fun.shape)
+        assert np.issubdtype(res.nit.dtype, np.integer)
+
+        ref_xl = [ref.xl for ref in refs]
+        assert_allclose(res.xl.ravel(), ref_xl)
+        assert_equal(res.xl.shape, shape)
+
+        ref_xr = [ref.xr for ref in refs]
+        assert_allclose(res.xr.ravel(), ref_xr)
+        assert_equal(res.xr.shape, shape)
+
+        assert_array_less(res.xl, res.xr)
+        finite = np.isfinite(res.x)
+        assert np.all((res.x[finite] == res.xl[finite])
+                      | (res.x[finite] == res.xr[finite]))
+
+        ref_fl = [ref.fl for ref in refs]
+        assert_allclose(res.fl.ravel(), ref_fl)
+        assert_equal(res.fl.shape, shape)
+        assert_allclose(res.fl, self.f(res.xl, *args))
+
+        ref_fr = [ref.fr for ref in refs]
+        assert_allclose(res.fr.ravel(), ref_fr)
+        assert_equal(res.fr.shape, shape)
+        assert_allclose(res.fr, self.f(res.xr, *args))
+
+        assert np.all(np.abs(res.fun[finite]) ==
+                      np.minimum(np.abs(res.fl[finite]),
+                                 np.abs(res.fr[finite])))
+
+    def test_flags(self):
+        # Test cases that should produce different status flags; show that all
+        # can be produced simultaneously.
+        def f(xs, js):
+            funcs = [lambda x: x - 2.5,
+                     lambda x: x - 10,
+                     lambda x: (x - 0.1)**3,
+                     lambda x: np.nan]
+            return [funcs[j](x) for x, j in zip(xs, js)]
+
+        args = (np.arange(4, dtype=np.int64),)
+        res = _chandrupatla_root(f, [0]*4, [np.pi]*4, args=args, maxiter=2)
+
+        ref_flags = np.array([eim._ECONVERGED,
+                              eim._ESIGNERR,
+                              eim._ECONVERR,
+                              eim._EVALUEERR])
+        assert_equal(res.status, ref_flags)
+
+    def test_convergence(self):
+        # Test that the convergence tolerances behave as expected
+        rng = np.random.default_rng(2585255913088665241)
+        p = rng.random(size=3)
+        bracket = (-5, 5)
+        args = (p,)
+        kwargs0 = dict(args=args, xatol=0, xrtol=0, fatol=0, frtol=0)
+
+        kwargs = kwargs0.copy()
+        kwargs['xatol'] = 1e-3
+        res1 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(res1.xr - res1.xl, 1e-3)
+        kwargs['xatol'] = 1e-6
+        res2 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(res2.xr - res2.xl, 1e-6)
+        assert_array_less(res2.xr - res2.xl, res1.xr - res1.xl)
+
+        kwargs = kwargs0.copy()
+        kwargs['xrtol'] = 1e-3
+        res1 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(res1.xr - res1.xl, 1e-3 * np.abs(res1.x))
+        kwargs['xrtol'] = 1e-6
+        res2 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(res2.xr - res2.xl, 1e-6 * np.abs(res2.x))
+        assert_array_less(res2.xr - res2.xl, res1.xr - res1.xl)
+
+        kwargs = kwargs0.copy()
+        kwargs['fatol'] = 1e-3
+        res1 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(np.abs(res1.fun), 1e-3)
+        kwargs['fatol'] = 1e-6
+        res2 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(np.abs(res2.fun), 1e-6)
+        assert_array_less(np.abs(res2.fun), np.abs(res1.fun))
+
+        kwargs = kwargs0.copy()
+        kwargs['frtol'] = 1e-3
+        x1, x2 = bracket
+        f0 = np.minimum(abs(self.f(x1, *args)), abs(self.f(x2, *args)))
+        res1 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(np.abs(res1.fun), 1e-3*f0)
+        kwargs['frtol'] = 1e-6
+        res2 = _chandrupatla_root(self.f, *bracket, **kwargs)
+        assert_array_less(np.abs(res2.fun), 1e-6*f0)
+        assert_array_less(np.abs(res2.fun), np.abs(res1.fun))
+
+    def test_maxiter_callback(self):
+        # Test behavior of `maxiter` parameter and `callback` interface
+        p = 0.612814
+        bracket = (-5, 5)
+        maxiter = 5
+
+        def f(q, p):
+            res = stats.norm().cdf(q) - p
+            f.x = q
+            f.fun = res
+            return res
+        f.x = None
+        f.fun = None
+
+        res = _chandrupatla_root(f, *bracket, args=(p,),
+                                  maxiter=maxiter)
+        assert not np.any(res.success)
+        assert np.all(res.nfev == maxiter+2)
+        assert np.all(res.nit == maxiter)
+
+        def callback(res):
+            callback.iter += 1
+            callback.res = res
+            assert hasattr(res, 'x')
+            if callback.iter == 0:
+                # callback is called once with initial bracket
+                assert (res.xl, res.xr) == bracket
+            else:
+                changed = (((res.xl == callback.xl) & (res.xr != callback.xr))
+                           | ((res.xl != callback.xl) & (res.xr == callback.xr)))
+                assert np.all(changed)
+
+            callback.xl = res.xl
+            callback.xr = res.xr
+            assert res.status == eim._EINPROGRESS
+            assert_equal(self.f(res.xl, p), res.fl)
+            assert_equal(self.f(res.xr, p), res.fr)
+            assert_equal(self.f(res.x, p), res.fun)
+            if callback.iter == maxiter:
+                raise StopIteration
+        callback.iter = -1  # callback called once before first iteration
+        callback.res = None
+        callback.xl = None
+        callback.xr = None
+
+        res2 = _chandrupatla_root(f, *bracket, args=(p,),
+                                   callback=callback)
+
+        # terminating with callback is identical to terminating due to maxiter
+        # (except for `status`)
+        for key in res.keys():
+            if key == 'status':
+                assert res[key] == eim._ECONVERR
+                assert callback.res[key] == eim._EINPROGRESS
+                assert res2[key] == eim._ECALLBACK
+            else:
+                assert res2[key] == callback.res[key] == res[key]
+
+    @pytest.mark.parametrize('case', _CHANDRUPATLA_TESTS)
+    def test_nit_expected(self, case):
+        # Test that `_chandrupatla` implements Chandrupatla's algorithm:
+        # in all 40 test cases, the number of iterations performed
+        # matches the number reported in the original paper.
+        f, bracket, root, nfeval, id = case
+        # Chandrupatla's criterion is equivalent to
+        # abs(x2-x1) < 4*abs(xmin)*xrtol + xatol, but we use the more standard
+        # abs(x2-x1) < abs(xmin)*xrtol + xatol. Therefore, set xrtol to 4x
+        # that used by Chandrupatla in tests.
+        res = _chandrupatla_root(f, *bracket, xrtol=4e-10, xatol=1e-5)
+        assert_allclose(res.fun, f(root), rtol=1e-8, atol=2e-3)
+        assert_equal(res.nfev, nfeval)
+
+    @pytest.mark.parametrize("root", (0.622, [0.622, 0.623]))
+    @pytest.mark.parametrize("dtype", (np.float16, np.float32, np.float64))
+    def test_dtype(self, root, dtype):
+        # Test that dtypes are preserved
+
+        root = dtype(root)
+        def f(x, root):
+            return ((x - root) ** 3).astype(dtype)
+
+        res = _chandrupatla_root(f, dtype(-3), dtype(5),
+                                  args=(root,), xatol=1e-3)
+        assert res.x.dtype == dtype
+        assert np.allclose(res.x, root, atol=1e-3) or np.all(res.fun == 0)
+
+    def test_input_validation(self):
+        # Test input validation for appropriate error messages
+
+        message = '`func` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(None, -4, 4)
+
+        message = 'Abscissae and function output must be real numbers.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4+1j, 4)
+
+        message = "shape mismatch: objects cannot be broadcast"
+        # raised by `np.broadcast, but the traceback is readable IMO
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, [-2, -3], [3, 4, 5])
+
+        message = "The shape of the array returned by `func`..."
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: [x[0], x[1], x[1]], [-3, -3], [5, 5])
+
+        message = 'Tolerances must be non-negative scalars.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, xatol=-1)
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, xrtol=np.nan)
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, fatol='ekki')
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, frtol=np.nan)
+
+        message = '`maxiter` must be a non-negative integer.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, maxiter=1.5)
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, maxiter=-1)
+
+        message = '`callback` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            _chandrupatla_root(lambda x: x, -4, 4, callback='shrubbery')
+
+    def test_special_cases(self):
+        # Test edge cases and other special cases
+
+        # Test that integers are not passed to `f`
+        # (otherwise this would overflow)
+        def f(x):
+            assert np.issubdtype(x.dtype, np.floating)
+            return x ** 99 - 1
+
+        res = _chandrupatla_root(f, -7, 5)
+        assert res.success
+        assert_allclose(res.x, 1)
+
+        # Test that if both ends of bracket equal root, algorithm reports
+        # convergence
+        def f(x):
+            return x**2 - 1
+
+        res = _chandrupatla_root(f, 1, 1)
+        assert res.success
+        assert_equal(res.x, 1)
+
+        def f(x):
+            return 1/x
+
+        with np.errstate(invalid='ignore'):
+            res = _chandrupatla_root(f, np.inf, np.inf)
+        assert res.success
+        assert_equal(res.x, np.inf)
+
+        # Test maxiter = 0. Should do nothing to bracket.
+        def f(x):
+            return x**3 - 1
+
+        bracket = (-3, 5)
+        res = _chandrupatla_root(f, *bracket, maxiter=0)
+        assert res.xl, res.xr == bracket
+        assert res.nit == 0
+        assert res.nfev == 2
+        assert res.status == -2
+        assert res.x == -3  # best so far
+
+        # Test maxiter = 1
+        res = _chandrupatla_root(f, *bracket, maxiter=1)
+        assert res.success
+        assert res.status == 0
+        assert res.nit == 1
+        assert res.nfev == 3
+        assert_allclose(res.x, 1)
+
+        # Test scalar `args` (not in tuple)
+        def f(x, c):
+            return c*x - 1
+
+        res = _chandrupatla_root(f, -1, 1, args=3)
+        assert_allclose(res.x, 1/3)
+
+        # # TODO: Test zero tolerance
+        # # ~~What's going on here - why are iterations repeated?~~
+        # # tl goes to zero when xatol=xrtol=0. When function is nearly linear,
+        # # this causes convergence issues.
+        # def f(x):
+        #     return np.cos(x)
+        #
+        # res = _chandrupatla_root(f, 0, np.pi, xatol=0, xrtol=0)
+        # assert res.nit < 100
+        # xp = np.nextafter(res.x, np.inf)
+        # xm = np.nextafter(res.x, -np.inf)
+        # assert np.abs(res.fun) < np.abs(f(xp))
+        # assert np.abs(res.fun) < np.abs(f(xm))

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_cobyla.py

@@ -0,0 +1,166 @@
+import math
+
+import numpy as np
+from numpy.testing import assert_allclose, assert_, assert_array_equal
+import pytest
+
+from scipy.optimize import fmin_cobyla, minimize, Bounds
+
+
+class TestCobyla:
+    def setup_method(self):
+        self.x0 = [4.95, 0.66]
+        self.solution = [math.sqrt(25 - (2.0/3)**2), 2.0/3]
+        self.opts = {'disp': False, 'rhobeg': 1, 'tol': 1e-5,
+                     'maxiter': 100}
+
+    def fun(self, x):
+        return x[0]**2 + abs(x[1])**3
+
+    def con1(self, x):
+        return x[0]**2 + x[1]**2 - 25
+
+    def con2(self, x):
+        return -self.con1(x)
+
+    @pytest.mark.xslow(True, reason='not slow, but noisy so only run rarely')
+    def test_simple(self, capfd):
+        # use disp=True as smoke test for gh-8118
+        x = fmin_cobyla(self.fun, self.x0, [self.con1, self.con2], rhobeg=1,
+                        rhoend=1e-5, maxfun=100, disp=True)
+        assert_allclose(x, self.solution, atol=1e-4)
+
+    def test_minimize_simple(self):
+        class Callback:
+            def __init__(self):
+                self.n_calls = 0
+                self.last_x = None
+
+            def __call__(self, x):
+                self.n_calls += 1
+                self.last_x = x
+
+        callback = Callback()
+
+        # Minimize with method='COBYLA'
+        cons = ({'type': 'ineq', 'fun': self.con1},
+                {'type': 'ineq', 'fun': self.con2})
+        sol = minimize(self.fun, self.x0, method='cobyla', constraints=cons,
+                       callback=callback, options=self.opts)
+        assert_allclose(sol.x, self.solution, atol=1e-4)
+        assert_(sol.success, sol.message)
+        assert_(sol.maxcv < 1e-5, sol)
+        assert_(sol.nfev < 70, sol)
+        assert_(sol.fun < self.fun(self.solution) + 1e-3, sol)
+        assert_(sol.nfev == callback.n_calls,
+                "Callback is not called exactly once for every function eval.")
+        assert_array_equal(
+            sol.x,
+            callback.last_x,
+            "Last design vector sent to the callback is not equal to returned value.",
+        )
+
+    def test_minimize_constraint_violation(self):
+        np.random.seed(1234)
+        pb = np.random.rand(10, 10)
+        spread = np.random.rand(10)
+
+        def p(w):
+            return pb.dot(w)
+
+        def f(w):
+            return -(w * spread).sum()
+
+        def c1(w):
+            return 500 - abs(p(w)).sum()
+
+        def c2(w):
+            return 5 - abs(p(w).sum())
+
+        def c3(w):
+            return 5 - abs(p(w)).max()
+
+        cons = ({'type': 'ineq', 'fun': c1},
+                {'type': 'ineq', 'fun': c2},
+                {'type': 'ineq', 'fun': c3})
+        w0 = np.zeros((10,))
+        sol = minimize(f, w0, method='cobyla', constraints=cons,
+                       options={'catol': 1e-6})
+        assert_(sol.maxcv > 1e-6)
+        assert_(not sol.success)
+
+
+def test_vector_constraints():
+    # test that fmin_cobyla and minimize can take a combination
+    # of constraints, some returning a number and others an array
+    def fun(x):
+        return (x[0] - 1)**2 + (x[1] - 2.5)**2
+
+    def fmin(x):
+        return fun(x) - 1
+
+    def cons1(x):
+        a = np.array([[1, -2, 2], [-1, -2, 6], [-1, 2, 2]])
+        return np.array([a[i, 0] * x[0] + a[i, 1] * x[1] +
+                         a[i, 2] for i in range(len(a))])
+
+    def cons2(x):
+        return x     # identity, acts as bounds x > 0
+
+    x0 = np.array([2, 0])
+    cons_list = [fun, cons1, cons2]
+
+    xsol = [1.4, 1.7]
+    fsol = 0.8
+
+    # testing fmin_cobyla
+    sol = fmin_cobyla(fun, x0, cons_list, rhoend=1e-5)
+    assert_allclose(sol, xsol, atol=1e-4)
+
+    sol = fmin_cobyla(fun, x0, fmin, rhoend=1e-5)
+    assert_allclose(fun(sol), 1, atol=1e-4)
+
+    # testing minimize
+    constraints = [{'type': 'ineq', 'fun': cons} for cons in cons_list]
+    sol = minimize(fun, x0, constraints=constraints, tol=1e-5)
+    assert_allclose(sol.x, xsol, atol=1e-4)
+    assert_(sol.success, sol.message)
+    assert_allclose(sol.fun, fsol, atol=1e-4)
+
+    constraints = {'type': 'ineq', 'fun': fmin}
+    sol = minimize(fun, x0, constraints=constraints, tol=1e-5)
+    assert_allclose(sol.fun, 1, atol=1e-4)
+
+
+class TestBounds:
+    # Test cobyla support for bounds (only when used via `minimize`)
+    # Invalid bounds is tested in
+    # test_optimize.TestOptimizeSimple.test_minimize_invalid_bounds
+
+    def test_basic(self):
+        def f(x):
+            return np.sum(x**2)
+
+        lb = [-1, None, 1, None, -0.5]
+        ub = [-0.5, -0.5, None, None, -0.5]
+        bounds = [(a, b) for a, b in zip(lb, ub)]
+        # these are converted to Bounds internally
+
+        res = minimize(f, x0=[1, 2, 3, 4, 5], method='cobyla', bounds=bounds)
+        ref = [-0.5, -0.5, 1, 0, -0.5]
+        assert res.success
+        assert_allclose(res.x, ref, atol=1e-3)
+
+    def test_unbounded(self):
+        def f(x):
+            return np.sum(x**2)
+
+        bounds = Bounds([-np.inf, -np.inf], [np.inf, np.inf])
+        res = minimize(f, x0=[1, 2], method='cobyla', bounds=bounds)
+        assert res.success
+        assert_allclose(res.x, 0, atol=1e-3)
+
+        bounds = Bounds([1, -np.inf], [np.inf, np.inf])
+        res = minimize(f, x0=[1, 2], method='cobyla', bounds=bounds)
+        assert res.success
+        assert_allclose(res.x, [1, 0], atol=1e-3)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_constraint_conversion.py

@@ -0,0 +1,274 @@
+"""
+Unit test for constraint conversion
+"""
+
+import numpy as np
+from numpy.testing import (assert_array_almost_equal,
+                           assert_allclose, assert_warns, suppress_warnings)
+import pytest
+from scipy.optimize import (NonlinearConstraint, LinearConstraint,
+                            OptimizeWarning, minimize, BFGS)
+from .test_minimize_constrained import (Maratos, HyperbolicIneq, Rosenbrock,
+                                        IneqRosenbrock, EqIneqRosenbrock,
+                                        BoundedRosenbrock, Elec)
+
+
+class TestOldToNew:
+    x0 = (2, 0)
+    bnds = ((0, None), (0, None))
+    method = "trust-constr"
+
+    def test_constraint_dictionary_1(self):
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2
+        cons = ({'type': 'ineq', 'fun': lambda x: x[0] - 2 * x[1] + 2},
+                {'type': 'ineq', 'fun': lambda x: -x[0] - 2 * x[1] + 6},
+                {'type': 'ineq', 'fun': lambda x: -x[0] + 2 * x[1] + 2})
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning, "delta_grad == 0.0")
+            res = minimize(fun, self.x0, method=self.method,
+                           bounds=self.bnds, constraints=cons)
+        assert_allclose(res.x, [1.4, 1.7], rtol=1e-4)
+        assert_allclose(res.fun, 0.8, rtol=1e-4)
+
+    def test_constraint_dictionary_2(self):
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2
+        cons = {'type': 'eq',
+                'fun': lambda x, p1, p2: p1*x[0] - p2*x[1],
+                'args': (1, 1.1),
+                'jac': lambda x, p1, p2: np.array([[p1, -p2]])}
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning, "delta_grad == 0.0")
+            res = minimize(fun, self.x0, method=self.method,
+                           bounds=self.bnds, constraints=cons)
+        assert_allclose(res.x, [1.7918552, 1.62895927])
+        assert_allclose(res.fun, 1.3857466063348418)
+
+    def test_constraint_dictionary_3(self):
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2
+        cons = [{'type': 'ineq', 'fun': lambda x: x[0] - 2 * x[1] + 2},
+                NonlinearConstraint(lambda x: x[0] - x[1], 0, 0)]
+
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning, "delta_grad == 0.0")
+            res = minimize(fun, self.x0, method=self.method,
+                           bounds=self.bnds, constraints=cons)
+        assert_allclose(res.x, [1.75, 1.75], rtol=1e-4)
+        assert_allclose(res.fun, 1.125, rtol=1e-4)
+
+
+class TestNewToOld:
+
+    def test_multiple_constraint_objects(self):
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2 + (x[2] - 0.75) ** 2
+        x0 = [2, 0, 1]
+        coni = []  # only inequality constraints (can use cobyla)
+        methods = ["slsqp", "cobyla", "trust-constr"]
+
+        # mixed old and new
+        coni.append([{'type': 'ineq', 'fun': lambda x: x[0] - 2 * x[1] + 2},
+                     NonlinearConstraint(lambda x: x[0] - x[1], -1, 1)])
+
+        coni.append([LinearConstraint([1, -2, 0], -2, np.inf),
+                     NonlinearConstraint(lambda x: x[0] - x[1], -1, 1)])
+
+        coni.append([NonlinearConstraint(lambda x: x[0] - 2 * x[1] + 2, 0, np.inf),
+                     NonlinearConstraint(lambda x: x[0] - x[1], -1, 1)])
+
+        for con in coni:
+            funs = {}
+            for method in methods:
+                with suppress_warnings() as sup:
+                    sup.filter(UserWarning)
+                    result = minimize(fun, x0, method=method, constraints=con)
+                    funs[method] = result.fun
+            assert_allclose(funs['slsqp'], funs['trust-constr'], rtol=1e-4)
+            assert_allclose(funs['cobyla'], funs['trust-constr'], rtol=1e-4)
+
+    def test_individual_constraint_objects(self):
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2 + (x[2] - 0.75) ** 2
+        x0 = [2, 0, 1]
+
+        cone = []  # with equality constraints (can't use cobyla)
+        coni = []  # only inequality constraints (can use cobyla)
+        methods = ["slsqp", "cobyla", "trust-constr"]
+
+        # nonstandard data types for constraint equality bounds
+        cone.append(NonlinearConstraint(lambda x: x[0] - x[1], 1, 1))
+        cone.append(NonlinearConstraint(lambda x: x[0] - x[1], [1.21], [1.21]))
+        cone.append(NonlinearConstraint(lambda x: x[0] - x[1],
+                                        1.21, np.array([1.21])))
+
+        # multiple equalities
+        cone.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    1.21, 1.21))  # two same equalities
+        cone.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    [1.21, 1.4], [1.21, 1.4]))  # two different equalities
+        cone.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    [1.21, 1.21], 1.21))  # equality specified two ways
+        cone.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    [1.21, -np.inf], [1.21, np.inf]))  # equality + unbounded
+
+        # nonstandard data types for constraint inequality bounds
+        coni.append(NonlinearConstraint(lambda x: x[0] - x[1], 1.21, np.inf))
+        coni.append(NonlinearConstraint(lambda x: x[0] - x[1], [1.21], np.inf))
+        coni.append(NonlinearConstraint(lambda x: x[0] - x[1],
+                                        1.21, np.array([np.inf])))
+        coni.append(NonlinearConstraint(lambda x: x[0] - x[1], -np.inf, -3))
+        coni.append(NonlinearConstraint(lambda x: x[0] - x[1],
+                                        np.array(-np.inf), -3))
+
+        # multiple inequalities/equalities
+        coni.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    1.21, np.inf))  # two same inequalities
+        cone.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    [1.21, -np.inf], [1.21, 1.4]))  # mixed equality/inequality
+        coni.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    [1.1, .8], [1.2, 1.4]))  # bounded above and below
+        coni.append(NonlinearConstraint(
+                    lambda x: [x[0] - x[1], x[1] - x[2]],
+                    [-1.2, -1.4], [-1.1, -.8]))  # - bounded above and below
+
+        # quick check of LinearConstraint class (very little new code to test)
+        cone.append(LinearConstraint([1, -1, 0], 1.21, 1.21))
+        cone.append(LinearConstraint([[1, -1, 0], [0, 1, -1]], 1.21, 1.21))
+        cone.append(LinearConstraint([[1, -1, 0], [0, 1, -1]],
+                                     [1.21, -np.inf], [1.21, 1.4]))
+
+        for con in coni:
+            funs = {}
+            for method in methods:
+                with suppress_warnings() as sup:
+                    sup.filter(UserWarning)
+                    result = minimize(fun, x0, method=method, constraints=con)
+                    funs[method] = result.fun
+            assert_allclose(funs['slsqp'], funs['trust-constr'], rtol=1e-3)
+            assert_allclose(funs['cobyla'], funs['trust-constr'], rtol=1e-3)
+
+        for con in cone:
+            funs = {}
+            for method in methods[::2]:  # skip cobyla
+                with suppress_warnings() as sup:
+                    sup.filter(UserWarning)
+                    result = minimize(fun, x0, method=method, constraints=con)
+                    funs[method] = result.fun
+            assert_allclose(funs['slsqp'], funs['trust-constr'], rtol=1e-3)
+
+
+class TestNewToOldSLSQP:
+    method = 'slsqp'
+    elec = Elec(n_electrons=2)
+    elec.x_opt = np.array([-0.58438468, 0.58438466, 0.73597047,
+                           -0.73597044, 0.34180668, -0.34180667])
+    brock = BoundedRosenbrock()
+    brock.x_opt = [0, 0]
+    list_of_problems = [Maratos(),
+                        HyperbolicIneq(),
+                        Rosenbrock(),
+                        IneqRosenbrock(),
+                        EqIneqRosenbrock(),
+                        elec,
+                        brock
+                        ]
+
+    def test_list_of_problems(self):
+
+        for prob in self.list_of_problems:
+
+            with suppress_warnings() as sup:
+                sup.filter(UserWarning)
+                result = minimize(prob.fun, prob.x0,
+                                  method=self.method,
+                                  bounds=prob.bounds,
+                                  constraints=prob.constr)
+
+            assert_array_almost_equal(result.x, prob.x_opt, decimal=3)
+
+    def test_warn_mixed_constraints(self):
+        # warns about inefficiency of mixed equality/inequality constraints
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2 + (x[2] - 0.75) ** 2
+        cons = NonlinearConstraint(lambda x: [x[0]**2 - x[1], x[1] - x[2]],
+                                   [1.1, .8], [1.1, 1.4])
+        bnds = ((0, None), (0, None), (0, None))
+        with suppress_warnings() as sup:
+            sup.filter(UserWarning, "delta_grad == 0.0")
+            assert_warns(OptimizeWarning, minimize, fun, (2, 0, 1),
+                         method=self.method, bounds=bnds, constraints=cons)
+
+    def test_warn_ignored_options(self):
+        # warns about constraint options being ignored
+        def fun(x):
+            return (x[0] - 1) ** 2 + (x[1] - 2.5) ** 2 + (x[2] - 0.75) ** 2
+        x0 = (2, 0, 1)
+
+        if self.method == "slsqp":
+            bnds = ((0, None), (0, None), (0, None))
+        else:
+            bnds = None
+
+        cons = NonlinearConstraint(lambda x: x[0], 2, np.inf)
+        res = minimize(fun, x0, method=self.method,
+                       bounds=bnds, constraints=cons)
+        # no warnings without constraint options
+        assert_allclose(res.fun, 1)
+
+        cons = LinearConstraint([1, 0, 0], 2, np.inf)
+        res = minimize(fun, x0, method=self.method,
+                       bounds=bnds, constraints=cons)
+        # no warnings without constraint options
+        assert_allclose(res.fun, 1)
+
+        cons = []
+        cons.append(NonlinearConstraint(lambda x: x[0]**2, 2, np.inf,
+                                        keep_feasible=True))
+        cons.append(NonlinearConstraint(lambda x: x[0]**2, 2, np.inf,
+                                        hess=BFGS()))
+        cons.append(NonlinearConstraint(lambda x: x[0]**2, 2, np.inf,
+                                        finite_diff_jac_sparsity=42))
+        cons.append(NonlinearConstraint(lambda x: x[0]**2, 2, np.inf,
+                                        finite_diff_rel_step=42))
+        cons.append(LinearConstraint([1, 0, 0], 2, np.inf,
+                                     keep_feasible=True))
+        for con in cons:
+            assert_warns(OptimizeWarning, minimize, fun, x0,
+                         method=self.method, bounds=bnds, constraints=cons)
+
+
+class TestNewToOldCobyla:
+    method = 'cobyla'
+
+    list_of_problems = [
+                        Elec(n_electrons=2),
+                        Elec(n_electrons=4),
+                        ]
+
+    @pytest.mark.slow
+    def test_list_of_problems(self):
+
+        for prob in self.list_of_problems:
+
+            with suppress_warnings() as sup:
+                sup.filter(UserWarning)
+                truth = minimize(prob.fun, prob.x0,
+                                 method='trust-constr',
+                                 bounds=prob.bounds,
+                                 constraints=prob.constr)
+                result = minimize(prob.fun, prob.x0,
+                                  method=self.method,
+                                  bounds=prob.bounds,
+                                  constraints=prob.constr)
+
+            assert_allclose(result.fun, truth.fun, rtol=1e-3)

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_constraints.py

@@ -0,0 +1,255 @@
+import pytest
+import numpy as np
+from numpy.testing import TestCase, assert_array_equal
+import scipy.sparse as sps
+from scipy.optimize._constraints import (
+    Bounds, LinearConstraint, NonlinearConstraint, PreparedConstraint,
+    new_bounds_to_old, old_bound_to_new, strict_bounds)
+
+
+class TestStrictBounds(TestCase):
+    def test_scalarvalue_unique_enforce_feasibility(self):
+        m = 3
+        lb = 2
+        ub = 4
+        enforce_feasibility = False
+        strict_lb, strict_ub = strict_bounds(lb, ub,
+                                             enforce_feasibility,
+                                             m)
+        assert_array_equal(strict_lb, [-np.inf, -np.inf, -np.inf])
+        assert_array_equal(strict_ub, [np.inf, np.inf, np.inf])
+
+        enforce_feasibility = True
+        strict_lb, strict_ub = strict_bounds(lb, ub,
+                                             enforce_feasibility,
+                                             m)
+        assert_array_equal(strict_lb, [2, 2, 2])
+        assert_array_equal(strict_ub, [4, 4, 4])
+
+    def test_vectorvalue_unique_enforce_feasibility(self):
+        m = 3
+        lb = [1, 2, 3]
+        ub = [4, 5, 6]
+        enforce_feasibility = False
+        strict_lb, strict_ub = strict_bounds(lb, ub,
+                                              enforce_feasibility,
+                                              m)
+        assert_array_equal(strict_lb, [-np.inf, -np.inf, -np.inf])
+        assert_array_equal(strict_ub, [np.inf, np.inf, np.inf])
+
+        enforce_feasibility = True
+        strict_lb, strict_ub = strict_bounds(lb, ub,
+                                              enforce_feasibility,
+                                              m)
+        assert_array_equal(strict_lb, [1, 2, 3])
+        assert_array_equal(strict_ub, [4, 5, 6])
+
+    def test_scalarvalue_vector_enforce_feasibility(self):
+        m = 3
+        lb = 2
+        ub = 4
+        enforce_feasibility = [False, True, False]
+        strict_lb, strict_ub = strict_bounds(lb, ub,
+                                             enforce_feasibility,
+                                             m)
+        assert_array_equal(strict_lb, [-np.inf, 2, -np.inf])
+        assert_array_equal(strict_ub, [np.inf, 4, np.inf])
+
+    def test_vectorvalue_vector_enforce_feasibility(self):
+        m = 3
+        lb = [1, 2, 3]
+        ub = [4, 6, np.inf]
+        enforce_feasibility = [True, False, True]
+        strict_lb, strict_ub = strict_bounds(lb, ub,
+                                             enforce_feasibility,
+                                             m)
+        assert_array_equal(strict_lb, [1, -np.inf, 3])
+        assert_array_equal(strict_ub, [4, np.inf, np.inf])
+
+
+def test_prepare_constraint_infeasible_x0():
+    lb = np.array([0, 20, 30])
+    ub = np.array([0.5, np.inf, 70])
+    x0 = np.array([1, 2, 3])
+    enforce_feasibility = np.array([False, True, True], dtype=bool)
+    bounds = Bounds(lb, ub, enforce_feasibility)
+    pytest.raises(ValueError, PreparedConstraint, bounds, x0)
+
+    pc = PreparedConstraint(Bounds(lb, ub), [1, 2, 3])
+    assert (pc.violation([1, 2, 3]) > 0).any()
+    assert (pc.violation([0.25, 21, 31]) == 0).all()
+
+    x0 = np.array([1, 2, 3, 4])
+    A = np.array([[1, 2, 3, 4], [5, 0, 0, 6], [7, 0, 8, 0]])
+    enforce_feasibility = np.array([True, True, True], dtype=bool)
+    linear = LinearConstraint(A, -np.inf, 0, enforce_feasibility)
+    pytest.raises(ValueError, PreparedConstraint, linear, x0)
+
+    pc = PreparedConstraint(LinearConstraint(A, -np.inf, 0),
+                            [1, 2, 3, 4])
+    assert (pc.violation([1, 2, 3, 4]) > 0).any()
+    assert (pc.violation([-10, 2, -10, 4]) == 0).all()
+
+    def fun(x):
+        return A.dot(x)
+
+    def jac(x):
+        return A
+
+    def hess(x, v):
+        return sps.csr_matrix((4, 4))
+
+    nonlinear = NonlinearConstraint(fun, -np.inf, 0, jac, hess,
+                                    enforce_feasibility)
+    pytest.raises(ValueError, PreparedConstraint, nonlinear, x0)
+
+    pc = PreparedConstraint(nonlinear, [-10, 2, -10, 4])
+    assert (pc.violation([1, 2, 3, 4]) > 0).any()
+    assert (pc.violation([-10, 2, -10, 4]) == 0).all()
+
+
+def test_violation():
+    def cons_f(x):
+        return np.array([x[0] ** 2 + x[1], x[0] ** 2 - x[1]])
+
+    nlc = NonlinearConstraint(cons_f, [-1, -0.8500], [2, 2])
+    pc = PreparedConstraint(nlc, [0.5, 1])
+
+    assert_array_equal(pc.violation([0.5, 1]), [0., 0.])
+
+    np.testing.assert_almost_equal(pc.violation([0.5, 1.2]), [0., 0.1])
+
+    np.testing.assert_almost_equal(pc.violation([1.2, 1.2]), [0.64, 0])
+
+    np.testing.assert_almost_equal(pc.violation([0.1, -1.2]), [0.19, 0])
+
+    np.testing.assert_almost_equal(pc.violation([0.1, 2]), [0.01, 1.14])
+
+
+def test_new_bounds_to_old():
+    lb = np.array([-np.inf, 2, 3])
+    ub = np.array([3, np.inf, 10])
+
+    bounds = [(None, 3), (2, None), (3, 10)]
+    assert_array_equal(new_bounds_to_old(lb, ub, 3), bounds)
+
+    bounds_single_lb = [(-1, 3), (-1, None), (-1, 10)]
+    assert_array_equal(new_bounds_to_old(-1, ub, 3), bounds_single_lb)
+
+    bounds_no_lb = [(None, 3), (None, None), (None, 10)]
+    assert_array_equal(new_bounds_to_old(-np.inf, ub, 3), bounds_no_lb)
+
+    bounds_single_ub = [(None, 20), (2, 20), (3, 20)]
+    assert_array_equal(new_bounds_to_old(lb, 20, 3), bounds_single_ub)
+
+    bounds_no_ub = [(None, None), (2, None), (3, None)]
+    assert_array_equal(new_bounds_to_old(lb, np.inf, 3), bounds_no_ub)
+
+    bounds_single_both = [(1, 2), (1, 2), (1, 2)]
+    assert_array_equal(new_bounds_to_old(1, 2, 3), bounds_single_both)
+
+    bounds_no_both = [(None, None), (None, None), (None, None)]
+    assert_array_equal(new_bounds_to_old(-np.inf, np.inf, 3), bounds_no_both)
+
+
+def test_old_bounds_to_new():
+    bounds = ([1, 2], (None, 3), (-1, None))
+    lb_true = np.array([1, -np.inf, -1])
+    ub_true = np.array([2, 3, np.inf])
+
+    lb, ub = old_bound_to_new(bounds)
+    assert_array_equal(lb, lb_true)
+    assert_array_equal(ub, ub_true)
+
+    bounds = [(-np.inf, np.inf), (np.array([1]), np.array([1]))]
+    lb, ub = old_bound_to_new(bounds)
+
+    assert_array_equal(lb, [-np.inf, 1])
+    assert_array_equal(ub, [np.inf, 1])
+
+
+class TestBounds:
+    def test_repr(self):
+        # so that eval works
+        from numpy import array, inf  # noqa: F401
+        for args in (
+            (-1.0, 5.0),
+            (-1.0, np.inf, True),
+            (np.array([1.0, -np.inf]), np.array([2.0, np.inf])),
+            (np.array([1.0, -np.inf]), np.array([2.0, np.inf]),
+             np.array([True, False])),
+        ):
+            bounds = Bounds(*args)
+            bounds2 = eval(repr(Bounds(*args)))
+            assert_array_equal(bounds.lb, bounds2.lb)
+            assert_array_equal(bounds.ub, bounds2.ub)
+            assert_array_equal(bounds.keep_feasible, bounds2.keep_feasible)
+
+    def test_array(self):
+        # gh13501
+        b = Bounds(lb=[0.0, 0.0], ub=[1.0, 1.0])
+        assert isinstance(b.lb, np.ndarray)
+        assert isinstance(b.ub, np.ndarray)
+
+    def test_defaults(self):
+        b1 = Bounds()
+        b2 = Bounds(np.asarray(-np.inf), np.asarray(np.inf))
+        assert b1.lb == b2.lb
+        assert b1.ub == b2.ub
+
+    def test_input_validation(self):
+        message = "Lower and upper bounds must be dense arrays."
+        with pytest.raises(ValueError, match=message):
+            Bounds(sps.coo_array([1, 2]), [1, 2])
+        with pytest.raises(ValueError, match=message):
+            Bounds([1, 2], sps.coo_array([1, 2]))
+
+        message = "`keep_feasible` must be a dense array."
+        with pytest.raises(ValueError, match=message):
+            Bounds([1, 2], [1, 2], keep_feasible=sps.coo_array([True, True]))
+
+        message = "`lb`, `ub`, and `keep_feasible` must be broadcastable."
+        with pytest.raises(ValueError, match=message):
+            Bounds([1, 2], [1, 2, 3])
+
+    def test_residual(self):
+        bounds = Bounds(-2, 4)
+        x0 = [-1, 2]
+        np.testing.assert_allclose(bounds.residual(x0), ([1, 4], [5, 2]))
+
+
+class TestLinearConstraint:
+    def test_defaults(self):
+        A = np.eye(4)
+        lc = LinearConstraint(A)
+        lc2 = LinearConstraint(A, -np.inf, np.inf)
+        assert_array_equal(lc.lb, lc2.lb)
+        assert_array_equal(lc.ub, lc2.ub)
+
+    def test_input_validation(self):
+        A = np.eye(4)
+        message = "`lb`, `ub`, and `keep_feasible` must be broadcastable"
+        with pytest.raises(ValueError, match=message):
+            LinearConstraint(A, [1, 2], [1, 2, 3])
+
+        message = "Constraint limits must be dense arrays"
+        with pytest.raises(ValueError, match=message):
+            LinearConstraint(A, sps.coo_array([1, 2]), [2, 3])
+        with pytest.raises(ValueError, match=message):
+            LinearConstraint(A, [1, 2], sps.coo_array([2, 3]))
+
+        message = "`keep_feasible` must be a dense array"
+        with pytest.raises(ValueError, match=message):
+            keep_feasible = sps.coo_array([True, True])
+            LinearConstraint(A, [1, 2], [2, 3], keep_feasible=keep_feasible)
+
+        A = np.empty((4, 3, 5))
+        message = "`A` must have exactly two dimensions."
+        with pytest.raises(ValueError, match=message):
+            LinearConstraint(A)
+
+    def test_residual(self):
+        A = np.eye(2)
+        lc = LinearConstraint(A, -2, 4)
+        x0 = [-1, 2]
+        np.testing.assert_allclose(lc.residual(x0), ([1, 4], [5, 2]))

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_cython_optimize.py

@@ -0,0 +1,92 @@
+"""
+Test Cython optimize zeros API functions: ``bisect``, ``ridder``, ``brenth``,
+and ``brentq`` in `scipy.optimize.cython_optimize`, by finding the roots of a
+3rd order polynomial given a sequence of constant terms, ``a0``, and fixed 1st,
+2nd, and 3rd order terms in ``args``.
+
+.. math::
+
+    f(x, a0, args) =  ((args[2]*x + args[1])*x + args[0])*x + a0
+
+The 3rd order polynomial function is written in Cython and called in a Python
+wrapper named after the zero function. See the private ``_zeros`` Cython module
+in `scipy.optimize.cython_optimze` for more information.
+"""
+
+import numpy.testing as npt
+from scipy.optimize.cython_optimize import _zeros
+
+# CONSTANTS
+# Solve x**3 - A0 = 0  for A0 = [2.0, 2.1, ..., 2.9].
+# The ARGS have 3 elements just to show how this could be done for any cubic
+# polynomial.
+A0 = tuple(-2.0 - x/10.0 for x in range(10))  # constant term
+ARGS = (0.0, 0.0, 1.0)  # 1st, 2nd, and 3rd order terms
+XLO, XHI = 0.0, 2.0  # first and second bounds of zeros functions
+# absolute and relative tolerances and max iterations for zeros functions
+XTOL, RTOL, MITR = 0.001, 0.001, 10
+EXPECTED = [(-a0) ** (1.0/3.0) for a0 in A0]
+# = [1.2599210498948732,
+#    1.2805791649874942,
+#    1.300591446851387,
+#    1.3200061217959123,
+#    1.338865900164339,
+#    1.3572088082974532,
+#    1.375068867074141,
+#    1.3924766500838337,
+#    1.4094597464129783,
+#    1.4260431471424087]
+
+
+# test bisect
+def test_bisect():
+    npt.assert_allclose(
+        EXPECTED,
+        list(
+            _zeros.loop_example('bisect', A0, ARGS, XLO, XHI, XTOL, RTOL, MITR)
+        ),
+        rtol=RTOL, atol=XTOL
+    )
+
+
+# test ridder
+def test_ridder():
+    npt.assert_allclose(
+        EXPECTED,
+        list(
+            _zeros.loop_example('ridder', A0, ARGS, XLO, XHI, XTOL, RTOL, MITR)
+        ),
+        rtol=RTOL, atol=XTOL
+    )
+
+
+# test brenth
+def test_brenth():
+    npt.assert_allclose(
+        EXPECTED,
+        list(
+            _zeros.loop_example('brenth', A0, ARGS, XLO, XHI, XTOL, RTOL, MITR)
+        ),
+        rtol=RTOL, atol=XTOL
+    )
+
+
+# test brentq
+def test_brentq():
+    npt.assert_allclose(
+        EXPECTED,
+        list(
+            _zeros.loop_example('brentq', A0, ARGS, XLO, XHI, XTOL, RTOL, MITR)
+        ),
+        rtol=RTOL, atol=XTOL
+    )
+
+
+# test brentq with full output
+def test_brentq_full_output():
+    output = _zeros.full_output_example(
+        (A0[0],) + ARGS, XLO, XHI, XTOL, RTOL, MITR)
+    npt.assert_allclose(EXPECTED[0], output['root'], rtol=RTOL, atol=XTOL)
+    npt.assert_equal(6, output['iterations'])
+    npt.assert_equal(7, output['funcalls'])
+    npt.assert_equal(0, output['error_num'])

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_differentiable_functions.py

@@ -0,0 +1,758 @@
+import pytest
+import numpy as np
+from numpy.testing import (TestCase, assert_array_almost_equal,
+                           assert_array_equal, assert_, assert_allclose,
+                           assert_equal)
+from scipy.sparse import csr_matrix
+from scipy.sparse.linalg import LinearOperator
+from scipy.optimize._differentiable_functions import (ScalarFunction,
+                                                      VectorFunction,
+                                                      LinearVectorFunction,
+                                                      IdentityVectorFunction)
+from scipy.optimize import rosen, rosen_der, rosen_hess
+from scipy.optimize._hessian_update_strategy import BFGS
+
+
+class ExScalarFunction:
+
+    def __init__(self):
+        self.nfev = 0
+        self.ngev = 0
+        self.nhev = 0
+
+    def fun(self, x):
+        self.nfev += 1
+        return 2*(x[0]**2 + x[1]**2 - 1) - x[0]
+
+    def grad(self, x):
+        self.ngev += 1
+        return np.array([4*x[0]-1, 4*x[1]])
+
+    def hess(self, x):
+        self.nhev += 1
+        return 4*np.eye(2)
+
+
+class TestScalarFunction(TestCase):
+
+    def test_finite_difference_grad(self):
+        ex = ExScalarFunction()
+        nfev = 0
+        ngev = 0
+
+        x0 = [1.0, 0.0]
+        analit = ScalarFunction(ex.fun, x0, (), ex.grad,
+                                ex.hess, None, (-np.inf, np.inf))
+        nfev += 1
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev, nfev)
+        approx = ScalarFunction(ex.fun, x0, (), '2-point',
+                                ex.hess, None, (-np.inf, np.inf))
+        nfev += 3
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(analit.f, approx.f)
+        assert_array_almost_equal(analit.g, approx.g)
+
+        x = [10, 0.3]
+        f_analit = analit.fun(x)
+        g_analit = analit.grad(x)
+        nfev += 1
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        f_approx = approx.fun(x)
+        g_approx = approx.grad(x)
+        nfev += 3
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_almost_equal(f_analit, f_approx)
+        assert_array_almost_equal(g_analit, g_approx)
+
+        x = [2.0, 1.0]
+        g_analit = analit.grad(x)
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+
+        g_approx = approx.grad(x)
+        nfev += 3
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_almost_equal(g_analit, g_approx)
+
+        x = [2.5, 0.3]
+        f_analit = analit.fun(x)
+        g_analit = analit.grad(x)
+        nfev += 1
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        f_approx = approx.fun(x)
+        g_approx = approx.grad(x)
+        nfev += 3
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_almost_equal(f_analit, f_approx)
+        assert_array_almost_equal(g_analit, g_approx)
+
+        x = [2, 0.3]
+        f_analit = analit.fun(x)
+        g_analit = analit.grad(x)
+        nfev += 1
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        f_approx = approx.fun(x)
+        g_approx = approx.grad(x)
+        nfev += 3
+        ngev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_almost_equal(f_analit, f_approx)
+        assert_array_almost_equal(g_analit, g_approx)
+
+    def test_fun_and_grad(self):
+        ex = ExScalarFunction()
+
+        def fg_allclose(x, y):
+            assert_allclose(x[0], y[0])
+            assert_allclose(x[1], y[1])
+
+        # with analytic gradient
+        x0 = [2.0, 0.3]
+        analit = ScalarFunction(ex.fun, x0, (), ex.grad,
+                                ex.hess, None, (-np.inf, np.inf))
+
+        fg = ex.fun(x0), ex.grad(x0)
+        fg_allclose(analit.fun_and_grad(x0), fg)
+        assert analit.ngev == 1
+
+        x0[1] = 1.
+        fg = ex.fun(x0), ex.grad(x0)
+        fg_allclose(analit.fun_and_grad(x0), fg)
+
+        # with finite difference gradient
+        x0 = [2.0, 0.3]
+        sf = ScalarFunction(ex.fun, x0, (), '3-point',
+                                ex.hess, None, (-np.inf, np.inf))
+        assert sf.ngev == 1
+        fg = ex.fun(x0), ex.grad(x0)
+        fg_allclose(sf.fun_and_grad(x0), fg)
+        assert sf.ngev == 1
+
+        x0[1] = 1.
+        fg = ex.fun(x0), ex.grad(x0)
+        fg_allclose(sf.fun_and_grad(x0), fg)
+
+    def test_finite_difference_hess_linear_operator(self):
+        ex = ExScalarFunction()
+        nfev = 0
+        ngev = 0
+        nhev = 0
+
+        x0 = [1.0, 0.0]
+        analit = ScalarFunction(ex.fun, x0, (), ex.grad,
+                                ex.hess, None, (-np.inf, np.inf))
+        nfev += 1
+        ngev += 1
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev, nhev)
+        approx = ScalarFunction(ex.fun, x0, (), ex.grad,
+                                '2-point', None, (-np.inf, np.inf))
+        assert_(isinstance(approx.H, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_equal(analit.f, approx.f)
+            assert_array_almost_equal(analit.g, approx.g)
+            assert_array_almost_equal(analit.H.dot(v), approx.H.dot(v))
+        nfev += 1
+        ngev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [2.0, 1.0]
+        H_analit = analit.hess(x)
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        H_approx = approx.hess(x)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v))
+        ngev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [2.1, 1.2]
+        H_analit = analit.hess(x)
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        H_approx = approx.hess(x)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v))
+        ngev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [2.5, 0.3]
+        _ = analit.grad(x)
+        H_analit = analit.hess(x)
+        ngev += 1
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        _ = approx.grad(x)
+        H_approx = approx.hess(x)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v))
+        ngev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [5.2, 2.3]
+        _ = analit.grad(x)
+        H_analit = analit.hess(x)
+        ngev += 1
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        _ = approx.grad(x)
+        H_approx = approx.hess(x)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v))
+        ngev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.ngev, ngev)
+        assert_array_equal(analit.ngev+approx.ngev, ngev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+    def test_x_storage_overlap(self):
+        # Scalar_Function should not store references to arrays, it should
+        # store copies - this checks that updating an array in-place causes
+        # Scalar_Function.x to be updated.
+
+        def f(x):
+            return np.sum(np.asarray(x) ** 2)
+
+        x = np.array([1., 2., 3.])
+        sf = ScalarFunction(f, x, (), '3-point', lambda x: x, None, (-np.inf, np.inf))
+
+        assert x is not sf.x
+        assert_equal(sf.fun(x), 14.0)
+        assert x is not sf.x
+
+        x[0] = 0.
+        f1 = sf.fun(x)
+        assert_equal(f1, 13.0)
+
+        x[0] = 1
+        f2 = sf.fun(x)
+        assert_equal(f2, 14.0)
+        assert x is not sf.x
+
+        # now test with a HessianUpdate strategy specified
+        hess = BFGS()
+        x = np.array([1., 2., 3.])
+        sf = ScalarFunction(f, x, (), '3-point', hess, None, (-np.inf, np.inf))
+
+        assert x is not sf.x
+        assert_equal(sf.fun(x), 14.0)
+        assert x is not sf.x
+
+        x[0] = 0.
+        f1 = sf.fun(x)
+        assert_equal(f1, 13.0)
+
+        x[0] = 1
+        f2 = sf.fun(x)
+        assert_equal(f2, 14.0)
+        assert x is not sf.x
+
+        # gh13740 x is changed in user function
+        def ff(x):
+            x *= x    # overwrite x
+            return np.sum(x)
+
+        x = np.array([1., 2., 3.])
+        sf = ScalarFunction(
+            ff, x, (), '3-point', lambda x: x, None, (-np.inf, np.inf)
+        )
+        assert x is not sf.x
+        assert_equal(sf.fun(x), 14.0)
+        assert_equal(sf.x, np.array([1., 2., 3.]))
+        assert x is not sf.x
+
+    def test_lowest_x(self):
+        # ScalarFunction should remember the lowest func(x) visited.
+        x0 = np.array([2, 3, 4])
+        sf = ScalarFunction(rosen, x0, (), rosen_der, rosen_hess,
+                            None, None)
+        sf.fun([1, 1, 1])
+        sf.fun(x0)
+        sf.fun([1.01, 1, 1.0])
+        sf.grad([1.01, 1, 1.0])
+        assert_equal(sf._lowest_f, 0.0)
+        assert_equal(sf._lowest_x, [1.0, 1.0, 1.0])
+
+        sf = ScalarFunction(rosen, x0, (), '2-point', rosen_hess,
+                            None, (-np.inf, np.inf))
+        sf.fun([1, 1, 1])
+        sf.fun(x0)
+        sf.fun([1.01, 1, 1.0])
+        sf.grad([1.01, 1, 1.0])
+        assert_equal(sf._lowest_f, 0.0)
+        assert_equal(sf._lowest_x, [1.0, 1.0, 1.0])
+
+    def test_float_size(self):
+        x0 = np.array([2, 3, 4]).astype(np.float32)
+
+        # check that ScalarFunction/approx_derivative always send the correct
+        # float width
+        def rosen_(x):
+            assert x.dtype == np.float32
+            return rosen(x)
+
+        sf = ScalarFunction(rosen_, x0, (), '2-point', rosen_hess,
+                            None, (-np.inf, np.inf))
+        res = sf.fun(x0)
+        assert res.dtype == np.float32
+
+
+class ExVectorialFunction:
+
+    def __init__(self):
+        self.nfev = 0
+        self.njev = 0
+        self.nhev = 0
+
+    def fun(self, x):
+        self.nfev += 1
+        return np.array([2*(x[0]**2 + x[1]**2 - 1) - x[0],
+                         4*(x[0]**3 + x[1]**2 - 4) - 3*x[0]], dtype=x.dtype)
+
+    def jac(self, x):
+        self.njev += 1
+        return np.array([[4*x[0]-1, 4*x[1]],
+                         [12*x[0]**2-3, 8*x[1]]], dtype=x.dtype)
+
+    def hess(self, x, v):
+        self.nhev += 1
+        return v[0]*4*np.eye(2) + v[1]*np.array([[24*x[0], 0],
+                                                 [0, 8]])
+
+
+class TestVectorialFunction(TestCase):
+
+    def test_finite_difference_jac(self):
+        ex = ExVectorialFunction()
+        nfev = 0
+        njev = 0
+
+        x0 = [1.0, 0.0]
+        analit = VectorFunction(ex.fun, x0, ex.jac, ex.hess, None, None,
+                                (-np.inf, np.inf), None)
+        nfev += 1
+        njev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev, njev)
+        approx = VectorFunction(ex.fun, x0, '2-point', ex.hess, None, None,
+                                (-np.inf, np.inf), None)
+        nfev += 3
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(analit.f, approx.f)
+        assert_array_almost_equal(analit.J, approx.J)
+
+        x = [10, 0.3]
+        f_analit = analit.fun(x)
+        J_analit = analit.jac(x)
+        nfev += 1
+        njev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        f_approx = approx.fun(x)
+        J_approx = approx.jac(x)
+        nfev += 3
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_almost_equal(f_analit, f_approx)
+        assert_array_almost_equal(J_analit, J_approx, decimal=4)
+
+        x = [2.0, 1.0]
+        J_analit = analit.jac(x)
+        njev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        J_approx = approx.jac(x)
+        nfev += 3
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_almost_equal(J_analit, J_approx)
+
+        x = [2.5, 0.3]
+        f_analit = analit.fun(x)
+        J_analit = analit.jac(x)
+        nfev += 1
+        njev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        f_approx = approx.fun(x)
+        J_approx = approx.jac(x)
+        nfev += 3
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_almost_equal(f_analit, f_approx)
+        assert_array_almost_equal(J_analit, J_approx)
+
+        x = [2, 0.3]
+        f_analit = analit.fun(x)
+        J_analit = analit.jac(x)
+        nfev += 1
+        njev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        f_approx = approx.fun(x)
+        J_approx = approx.jac(x)
+        nfev += 3
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_almost_equal(f_analit, f_approx)
+        assert_array_almost_equal(J_analit, J_approx)
+
+    def test_finite_difference_hess_linear_operator(self):
+        ex = ExVectorialFunction()
+        nfev = 0
+        njev = 0
+        nhev = 0
+
+        x0 = [1.0, 0.0]
+        v0 = [1.0, 2.0]
+        analit = VectorFunction(ex.fun, x0, ex.jac, ex.hess, None, None,
+                                (-np.inf, np.inf), None)
+        nfev += 1
+        njev += 1
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev, nhev)
+        approx = VectorFunction(ex.fun, x0, ex.jac, '2-point', None, None,
+                                (-np.inf, np.inf), None)
+        assert_(isinstance(approx.H, LinearOperator))
+        for p in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_equal(analit.f, approx.f)
+            assert_array_almost_equal(analit.J, approx.J)
+            assert_array_almost_equal(analit.H.dot(p), approx.H.dot(p))
+        nfev += 1
+        njev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [2.0, 1.0]
+        H_analit = analit.hess(x, v0)
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        H_approx = approx.hess(x, v0)
+        assert_(isinstance(H_approx, LinearOperator))
+        for p in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(p), H_approx.dot(p),
+                                      decimal=5)
+        njev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [2.1, 1.2]
+        v = [1.0, 1.0]
+        H_analit = analit.hess(x, v)
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        H_approx = approx.hess(x, v)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v))
+        njev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [2.5, 0.3]
+        _ = analit.jac(x)
+        H_analit = analit.hess(x, v0)
+        njev += 1
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        _ = approx.jac(x)
+        H_approx = approx.hess(x, v0)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v), decimal=4)
+        njev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+        x = [5.2, 2.3]
+        v = [2.3, 5.2]
+        _ = analit.jac(x)
+        H_analit = analit.hess(x, v)
+        njev += 1
+        nhev += 1
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+        _ = approx.jac(x)
+        H_approx = approx.hess(x, v)
+        assert_(isinstance(H_approx, LinearOperator))
+        for v in ([1.0, 2.0], [3.0, 4.0], [5.0, 2.0]):
+            assert_array_almost_equal(H_analit.dot(v), H_approx.dot(v), decimal=4)
+        njev += 4
+        assert_array_equal(ex.nfev, nfev)
+        assert_array_equal(analit.nfev+approx.nfev, nfev)
+        assert_array_equal(ex.njev, njev)
+        assert_array_equal(analit.njev+approx.njev, njev)
+        assert_array_equal(ex.nhev, nhev)
+        assert_array_equal(analit.nhev+approx.nhev, nhev)
+
+    def test_x_storage_overlap(self):
+        # VectorFunction should not store references to arrays, it should
+        # store copies - this checks that updating an array in-place causes
+        # Scalar_Function.x to be updated.
+        ex = ExVectorialFunction()
+        x0 = np.array([1.0, 0.0])
+
+        vf = VectorFunction(ex.fun, x0, '3-point', ex.hess, None, None,
+                            (-np.inf, np.inf), None)
+
+        assert x0 is not vf.x
+        assert_equal(vf.fun(x0), ex.fun(x0))
+        assert x0 is not vf.x
+
+        x0[0] = 2.
+        assert_equal(vf.fun(x0), ex.fun(x0))
+        assert x0 is not vf.x
+
+        x0[0] = 1.
+        assert_equal(vf.fun(x0), ex.fun(x0))
+        assert x0 is not vf.x
+
+        # now test with a HessianUpdate strategy specified
+        hess = BFGS()
+        x0 = np.array([1.0, 0.0])
+        vf = VectorFunction(ex.fun, x0, '3-point', hess, None, None,
+                            (-np.inf, np.inf), None)
+
+        with pytest.warns(UserWarning):
+            # filter UserWarning because ExVectorialFunction is linear and
+            # a quasi-Newton approximation is used for the Hessian.
+            assert x0 is not vf.x
+            assert_equal(vf.fun(x0), ex.fun(x0))
+            assert x0 is not vf.x
+
+            x0[0] = 2.
+            assert_equal(vf.fun(x0), ex.fun(x0))
+            assert x0 is not vf.x
+
+            x0[0] = 1.
+            assert_equal(vf.fun(x0), ex.fun(x0))
+            assert x0 is not vf.x
+
+    def test_float_size(self):
+        ex = ExVectorialFunction()
+        x0 = np.array([1.0, 0.0]).astype(np.float32)
+
+        vf = VectorFunction(ex.fun, x0, ex.jac, ex.hess, None, None,
+                            (-np.inf, np.inf), None)
+
+        res = vf.fun(x0)
+        assert res.dtype == np.float32
+
+        res = vf.jac(x0)
+        assert res.dtype == np.float32
+
+
+def test_LinearVectorFunction():
+    A_dense = np.array([
+        [-1, 2, 0],
+        [0, 4, 2]
+    ])
+    x0 = np.zeros(3)
+    A_sparse = csr_matrix(A_dense)
+    x = np.array([1, -1, 0])
+    v = np.array([-1, 1])
+    Ax = np.array([-3, -4])
+
+    f1 = LinearVectorFunction(A_dense, x0, None)
+    assert_(not f1.sparse_jacobian)
+
+    f2 = LinearVectorFunction(A_dense, x0, True)
+    assert_(f2.sparse_jacobian)
+
+    f3 = LinearVectorFunction(A_dense, x0, False)
+    assert_(not f3.sparse_jacobian)
+
+    f4 = LinearVectorFunction(A_sparse, x0, None)
+    assert_(f4.sparse_jacobian)
+
+    f5 = LinearVectorFunction(A_sparse, x0, True)
+    assert_(f5.sparse_jacobian)
+
+    f6 = LinearVectorFunction(A_sparse, x0, False)
+    assert_(not f6.sparse_jacobian)
+
+    assert_array_equal(f1.fun(x), Ax)
+    assert_array_equal(f2.fun(x), Ax)
+    assert_array_equal(f1.jac(x), A_dense)
+    assert_array_equal(f2.jac(x).toarray(), A_sparse.toarray())
+    assert_array_equal(f1.hess(x, v).toarray(), np.zeros((3, 3)))
+
+
+def test_LinearVectorFunction_memoization():
+    A = np.array([[-1, 2, 0], [0, 4, 2]])
+    x0 = np.array([1, 2, -1])
+    fun = LinearVectorFunction(A, x0, False)
+
+    assert_array_equal(x0, fun.x)
+    assert_array_equal(A.dot(x0), fun.f)
+
+    x1 = np.array([-1, 3, 10])
+    assert_array_equal(A, fun.jac(x1))
+    assert_array_equal(x1, fun.x)
+    assert_array_equal(A.dot(x0), fun.f)
+    assert_array_equal(A.dot(x1), fun.fun(x1))
+    assert_array_equal(A.dot(x1), fun.f)
+
+
+def test_IdentityVectorFunction():
+    x0 = np.zeros(3)
+
+    f1 = IdentityVectorFunction(x0, None)
+    f2 = IdentityVectorFunction(x0, False)
+    f3 = IdentityVectorFunction(x0, True)
+
+    assert_(f1.sparse_jacobian)
+    assert_(not f2.sparse_jacobian)
+    assert_(f3.sparse_jacobian)
+
+    x = np.array([-1, 2, 1])
+    v = np.array([-2, 3, 0])
+
+    assert_array_equal(f1.fun(x), x)
+    assert_array_equal(f2.fun(x), x)
+
+    assert_array_equal(f1.jac(x).toarray(), np.eye(3))
+    assert_array_equal(f2.jac(x), np.eye(3))
+
+    assert_array_equal(f1.hess(x, v).toarray(), np.zeros((3, 3)))

llmeval-env/lib/python3.10/site-packages/scipy/optimize/tests/test_differentiate.py

@@ -0,0 +1,396 @@
+import pytest
+
+import numpy as np
+from numpy.testing import assert_array_less, assert_allclose, assert_equal
+
+import scipy._lib._elementwise_iterative_method as eim
+from scipy import stats
+from scipy.optimize._differentiate import (_differentiate as differentiate,
+                                           _EERRORINCREASE)
+
+class TestDifferentiate:
+
+    def f(self, x):
+        return stats.norm().cdf(x)
+
+    @pytest.mark.parametrize('x', [0.6, np.linspace(-0.05, 1.05, 10)])
+    def test_basic(self, x):
+        # Invert distribution CDF and compare against distribution `ppf`
+        res = differentiate(self.f, x)
+        ref = stats.norm().pdf(x)
+        np.testing.assert_allclose(res.df, ref)
+        # This would be nice, but doesn't always work out. `error` is an
+        # estimate, not a bound.
+        assert_array_less(abs(res.df - ref), res.error)
+        assert res.x.shape == ref.shape
+
+    @pytest.mark.parametrize('case', stats._distr_params.distcont)
+    def test_accuracy(self, case):
+        distname, params = case
+        dist = getattr(stats, distname)(*params)
+        x = dist.median() + 0.1
+        res = differentiate(dist.cdf, x)
+        ref = dist.pdf(x)
+        assert_allclose(res.df, ref, atol=1e-10)
+
+    @pytest.mark.parametrize('order', [1, 6])
+    @pytest.mark.parametrize('shape', [tuple(), (12,), (3, 4), (3, 2, 2)])
+    def test_vectorization(self, order, shape):
+        # Test for correct functionality, output shapes, and dtypes for various
+        # input shapes.
+        x = np.linspace(-0.05, 1.05, 12).reshape(shape) if shape else 0.6
+        n = np.size(x)
+
+        @np.vectorize
+        def _differentiate_single(x):
+            return differentiate(self.f, x, order=order)
+
+        def f(x, *args, **kwargs):
+            f.nit += 1
+            f.feval += 1 if (x.size == n or x.ndim <=1) else x.shape[-1]
+            return self.f(x, *args, **kwargs)
+        f.nit = -1
+        f.feval = 0
+
+        res = differentiate(f, x, order=order)
+        refs = _differentiate_single(x).ravel()
+
+        ref_x = [ref.x for ref in refs]
+        assert_allclose(res.x.ravel(), ref_x)
+        assert_equal(res.x.shape, shape)
+
+        ref_df = [ref.df for ref in refs]
+        assert_allclose(res.df.ravel(), ref_df)
+        assert_equal(res.df.shape, shape)
+
+        ref_error = [ref.error for ref in refs]
+        assert_allclose(res.error.ravel(), ref_error, atol=5e-15)
+        assert_equal(res.error.shape, shape)
+
+        ref_success = [ref.success for ref in refs]
+        assert_equal(res.success.ravel(), ref_success)
+        assert_equal(res.success.shape, shape)
+        assert np.issubdtype(res.success.dtype, np.bool_)
+
+        ref_flag = [ref.status for ref in refs]
+        assert_equal(res.status.ravel(), ref_flag)
+        assert_equal(res.status.shape, shape)
+        assert np.issubdtype(res.status.dtype, np.integer)
+
+        ref_nfev = [ref.nfev for ref in refs]
+        assert_equal(res.nfev.ravel(), ref_nfev)
+        assert_equal(np.max(res.nfev), f.feval)
+        assert_equal(res.nfev.shape, res.x.shape)
+        assert np.issubdtype(res.nfev.dtype, np.integer)
+
+        ref_nit = [ref.nit for ref in refs]
+        assert_equal(res.nit.ravel(), ref_nit)
+        assert_equal(np.max(res.nit), f.nit)
+        assert_equal(res.nit.shape, res.x.shape)
+        assert np.issubdtype(res.nit.dtype, np.integer)
+
+    def test_flags(self):
+        # Test cases that should produce different status flags; show that all
+        # can be produced simultaneously.
+        rng = np.random.default_rng(5651219684984213)
+        def f(xs, js):
+            f.nit += 1
+            funcs = [lambda x: x - 2.5,  # converges
+                     lambda x: np.exp(x)*rng.random(),  # error increases
+                     lambda x: np.exp(x),  # reaches maxiter due to order=2
+                     lambda x: np.full_like(x, np.nan)[()]]  # stops due to NaN
+            res = [funcs[j](x) for x, j in zip(xs, js.ravel())]
+            return res
+        f.nit = 0
+
+        args = (np.arange(4, dtype=np.int64),)
+        res = differentiate(f, [1]*4, rtol=1e-14, order=2, args=args)
+
+        ref_flags = np.array([eim._ECONVERGED,
+                              _EERRORINCREASE,
+                              eim._ECONVERR,
+                              eim._EVALUEERR])
+        assert_equal(res.status, ref_flags)
+
+    def test_flags_preserve_shape(self):
+        # Same test as above but using `preserve_shape` option to simplify.
+        rng = np.random.default_rng(5651219684984213)
+        def f(x):
+            return [x - 2.5,  # converges
+                    np.exp(x)*rng.random(),  # error increases
+                    np.exp(x),  # reaches maxiter due to order=2
+                    np.full_like(x, np.nan)[()]]  # stops due to NaN
+
+        res = differentiate(f, 1, rtol=1e-14, order=2, preserve_shape=True)
+
+        ref_flags = np.array([eim._ECONVERGED,
+                              _EERRORINCREASE,
+                              eim._ECONVERR,
+                              eim._EVALUEERR])
+        assert_equal(res.status, ref_flags)
+
+    def test_preserve_shape(self):
+        # Test `preserve_shape` option
+        def f(x):
+            return [x, np.sin(3*x), x+np.sin(10*x), np.sin(20*x)*(x-1)**2]
+
+        x = 0
+        ref = [1, 3*np.cos(3*x), 1+10*np.cos(10*x),
+               20*np.cos(20*x)*(x-1)**2 + 2*np.sin(20*x)*(x-1)]
+        res = differentiate(f, x, preserve_shape=True)
+        assert_allclose(res.df, ref)
+
+    def test_convergence(self):
+        # Test that the convergence tolerances behave as expected
+        dist = stats.norm()
+        x = 1
+        f = dist.cdf
+        ref = dist.pdf(x)
+        kwargs0 = dict(atol=0, rtol=0, order=4)
+
+        kwargs = kwargs0.copy()
+        kwargs['atol'] = 1e-3
+        res1 = differentiate(f, x, **kwargs)
+        assert_array_less(abs(res1.df - ref), 1e-3)
+        kwargs['atol'] = 1e-6
+        res2 = differentiate(f, x, **kwargs)
+        assert_array_less(abs(res2.df - ref), 1e-6)
+        assert_array_less(abs(res2.df - ref), abs(res1.df - ref))
+
+        kwargs = kwargs0.copy()
+        kwargs['rtol'] = 1e-3
+        res1 = differentiate(f, x, **kwargs)
+        assert_array_less(abs(res1.df - ref), 1e-3 * np.abs(ref))
+        kwargs['rtol'] = 1e-6
+        res2 = differentiate(f, x, **kwargs)
+        assert_array_less(abs(res2.df - ref), 1e-6 * np.abs(ref))
+        assert_array_less(abs(res2.df - ref), abs(res1.df - ref))
+
+    def test_step_parameters(self):
+        # Test that step factors have the expected effect on accuracy
+        dist = stats.norm()
+        x = 1
+        f = dist.cdf
+        ref = dist.pdf(x)
+
+        res1 = differentiate(f, x, initial_step=0.5, maxiter=1)
+        res2 = differentiate(f, x, initial_step=0.05, maxiter=1)
+        assert abs(res2.df - ref) < abs(res1.df - ref)
+
+        res1 = differentiate(f, x, step_factor=2, maxiter=1)
+        res2 = differentiate(f, x, step_factor=20, maxiter=1)
+        assert abs(res2.df - ref) < abs(res1.df - ref)
+
+        # `step_factor` can be less than 1: `initial_step` is the minimum step
+        kwargs = dict(order=4, maxiter=1, step_direction=0)
+        res = differentiate(f, x, initial_step=0.5, step_factor=0.5, **kwargs)
+        ref = differentiate(f, x, initial_step=1, step_factor=2, **kwargs)
+        assert_allclose(res.df, ref.df, rtol=5e-15)
+
+        # This is a similar test for one-sided difference
+        kwargs = dict(order=2, maxiter=1, step_direction=1)
+        res = differentiate(f, x, initial_step=1, step_factor=2, **kwargs)
+        ref = differentiate(f, x, initial_step=1/np.sqrt(2), step_factor=0.5,
+                                   **kwargs)
+        assert_allclose(res.df, ref.df, rtol=5e-15)
+
+        kwargs['step_direction'] = -1
+        res = differentiate(f, x, initial_step=1, step_factor=2, **kwargs)
+        ref = differentiate(f, x, initial_step=1/np.sqrt(2), step_factor=0.5,
+                                   **kwargs)
+        assert_allclose(res.df, ref.df, rtol=5e-15)
+
+    def test_step_direction(self):
+        # test that `step_direction` works as expected
+        def f(x):
+            y = np.exp(x)
+            y[(x < 0) + (x > 2)] = np.nan
+            return y
+
+        x = np.linspace(0, 2, 10)
+        step_direction = np.zeros_like(x)
+        step_direction[x < 0.6], step_direction[x > 1.4] = 1, -1
+        res = differentiate(f, x, step_direction=step_direction)
+        assert_allclose(res.df, np.exp(x))
+        assert np.all(res.success)
+
+    def test_vectorized_step_direction_args(self):
+        # test that `step_direction` and `args` are vectorized properly
+        def f(x, p):
+            return x ** p
+
+        def df(x, p):
+            return p * x ** (p - 1)
+
+        x = np.array([1, 2, 3, 4]).reshape(-1, 1, 1)
+        hdir = np.array([-1, 0, 1]).reshape(1, -1, 1)
+        p = np.array([2, 3]).reshape(1, 1, -1)
+        res = differentiate(f, x, step_direction=hdir, args=(p,))
+        ref = np.broadcast_to(df(x, p), res.df.shape)
+        assert_allclose(res.df, ref)
+
+    def test_maxiter_callback(self):
+        # Test behavior of `maxiter` parameter and `callback` interface
+        x = 0.612814
+        dist = stats.norm()
+        maxiter = 3
+
+        def f(x):
+            res = dist.cdf(x)
+            return res
+
+        default_order = 8
+        res = differentiate(f, x, maxiter=maxiter, rtol=1e-15)
+        assert not np.any(res.success)
+        assert np.all(res.nfev == default_order + 1 + (maxiter - 1)*2)
+        assert np.all(res.nit == maxiter)
+
+        def callback(res):
+            callback.iter += 1
+            callback.res = res
+            assert hasattr(res, 'x')
+            assert res.df not in callback.dfs
+            callback.dfs.add(res.df)
+            assert res.status == eim._EINPROGRESS
+            if callback.iter == maxiter:
+                raise StopIteration
+        callback.iter = -1  # callback called once before first iteration
+        callback.res = None
+        callback.dfs = set()
+
+        res2 = differentiate(f, x, callback=callback, rtol=1e-15)
+        # terminating with callback is identical to terminating due to maxiter
+        # (except for `status`)
+        for key in res.keys():
+            if key == 'status':
+                assert res[key] == eim._ECONVERR
+                assert callback.res[key] == eim._EINPROGRESS
+                assert res2[key] == eim._ECALLBACK
+            else:
+                assert res2[key] == callback.res[key] == res[key]
+
+    @pytest.mark.parametrize("hdir", (-1, 0, 1))
+    @pytest.mark.parametrize("x", (0.65, [0.65, 0.7]))
+    @pytest.mark.parametrize("dtype", (np.float16, np.float32, np.float64))
+    def test_dtype(self, hdir, x, dtype):
+        # Test that dtypes are preserved
+        x = np.asarray(x, dtype=dtype)[()]
+
+        def f(x):
+            assert x.dtype == dtype
+            return np.exp(x)
+
+        def callback(res):
+            assert res.x.dtype == dtype
+            assert res.df.dtype == dtype
+            assert res.error.dtype == dtype
+
+        res = differentiate(f, x, order=4, step_direction=hdir,
+                                   callback=callback)
+        assert res.x.dtype == dtype
+        assert res.df.dtype == dtype
+        assert res.error.dtype == dtype
+        eps = np.finfo(dtype).eps
+        assert_allclose(res.df, np.exp(res.x), rtol=np.sqrt(eps))
+
+    def test_input_validation(self):
+        # Test input validation for appropriate error messages
+
+        message = '`func` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            differentiate(None, 1)
+
+        message = 'Abscissae and function output must be real numbers.'
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, -4+1j)
+
+        message = "When `preserve_shape=False`, the shape of the array..."
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: [1, 2, 3], [-2, -3])
+
+        message = 'Tolerances and step parameters must be non-negative...'
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, atol=-1)
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, rtol='ekki')
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, initial_step=None)
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, step_factor=object())
+
+        message = '`maxiter` must be a positive integer.'
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, maxiter=1.5)
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, maxiter=0)
+
+        message = '`order` must be a positive integer'
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, order=1.5)
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, order=0)
+
+        message = '`preserve_shape` must be True or False.'
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, preserve_shape='herring')
+
+        message = '`callback` must be callable.'
+        with pytest.raises(ValueError, match=message):
+            differentiate(lambda x: x, 1, callback='shrubbery')
+
+    def test_special_cases(self):
+        # Test edge cases and other special cases
+
+        # Test that integers are not passed to `f`
+        # (otherwise this would overflow)
+        def f(x):
+            assert np.issubdtype(x.dtype, np.floating)
+            return x ** 99 - 1
+
+        res = differentiate(f, 7, rtol=1e-10)
+        assert res.success
+        assert_allclose(res.df, 99*7.**98)
+
+        # Test that if success is achieved in the correct number
+        # of iterations if function is a polynomial. Ideally, all polynomials
+        # of order 0-2 would get exact result with 0 refinement iterations,
+        # all polynomials of order 3-4 would be differentiated exactly after
+        # 1 iteration, etc. However, it seems that _differentiate needs an
+        # extra iteration to detect convergence based on the error estimate.
+
+        for n in range(6):
+            x = 1.5
+            def f(x):
+                return 2*x**n
+
+            ref = 2*n*x**(n-1)
+
+            res = differentiate(f, x, maxiter=1, order=max(1, n))
+            assert_allclose(res.df, ref, rtol=1e-15)
+            assert_equal(res.error, np.nan)
+
+            res = differentiate(f, x, order=max(1, n))
+            assert res.success
+            assert res.nit == 2
+            assert_allclose(res.df, ref, rtol=1e-15)
+
+        # Test scalar `args` (not in tuple)
+        def f(x, c):
+            return c*x - 1
+
+        res = differentiate(f, 2, args=3)
+        assert_allclose(res.df, 3)
+
+    @pytest.mark.xfail
+    @pytest.mark.parametrize("case", (  # function, evaluation point
+        (lambda x: (x - 1) ** 3, 1),
+        (lambda x: np.where(x > 1, (x - 1) ** 5, (x - 1) ** 3), 1)
+    ))
+    def test_saddle_gh18811(self, case):
+        # With default settings, _differentiate will not always converge when
+        # the true derivative is exactly zero. This tests that specifying a
+        # (tight) `atol` alleviates the problem. See discussion in gh-18811.
+        atol = 1e-16
+        res = differentiate(*case, step_direction=[-1, 0, 1], atol=atol)
+        assert np.all(res.success)
+        assert_allclose(res.df, 0, atol=atol)