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  1. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__init__.py +25 -0
  2. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/__init__.cpython-310.pyc +0 -0
  3. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/accumulationbounds.cpython-310.pyc +0 -0
  4. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/euler.cpython-310.pyc +0 -0
  5. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/finite_diff.cpython-310.pyc +0 -0
  6. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/singularities.cpython-310.pyc +0 -0
  7. llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/util.cpython-310.pyc +0 -0
  8. llmeval-env/lib/python3.10/site-packages/sympy/calculus/accumulationbounds.py +805 -0
  9. llmeval-env/lib/python3.10/site-packages/sympy/calculus/euler.py +108 -0
  10. llmeval-env/lib/python3.10/site-packages/sympy/calculus/finite_diff.py +476 -0
  11. llmeval-env/lib/python3.10/site-packages/sympy/calculus/singularities.py +398 -0
  12. llmeval-env/lib/python3.10/site-packages/sympy/calculus/tests/test_accumulationbounds.py +336 -0
  13. llmeval-env/lib/python3.10/site-packages/sympy/calculus/tests/test_euler.py +74 -0
  14. llmeval-env/lib/python3.10/site-packages/sympy/calculus/tests/test_singularities.py +103 -0
  15. llmeval-env/lib/python3.10/site-packages/sympy/calculus/util.py +841 -0
  16. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__init__.py +18 -0
  17. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/__init__.cpython-310.pyc +0 -0
  18. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/holonomic.cpython-310.pyc +0 -0
  19. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/holonomicerrors.cpython-310.pyc +0 -0
  20. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/numerical.cpython-310.pyc +0 -0
  21. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/recurrence.cpython-310.pyc +0 -0
  22. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/holonomic.py +2899 -0
  23. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/holonomicerrors.py +49 -0
  24. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/numerical.py +109 -0
  25. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/recurrence.py +365 -0
  26. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/__init__.py +0 -0
  27. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/__pycache__/__init__.cpython-310.pyc +0 -0
  28. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/__pycache__/test_holonomic.cpython-310.pyc +0 -0
  29. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/__pycache__/test_recurrence.cpython-310.pyc +0 -0
  30. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/test_holonomic.py +830 -0
  31. llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/test_recurrence.py +29 -0
  32. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/__init__.cpython-310.pyc +0 -0
  33. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/decompositions.cpython-310.pyc +0 -0
  34. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/dense.cpython-310.pyc +0 -0
  35. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/immutable.cpython-310.pyc +0 -0
  36. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/inverse.cpython-310.pyc +0 -0
  37. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/normalforms.cpython-310.pyc +0 -0
  38. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/repmatrix.cpython-310.pyc +0 -0
  39. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/solvers.cpython-310.pyc +0 -0
  40. llmeval-env/lib/python3.10/site-packages/sympy/matrices/__pycache__/utilities.cpython-310.pyc +0 -0
  41. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__init__.py +0 -0
  42. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/__init__.cpython-310.pyc +0 -0
  43. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_commonmatrix.cpython-310.pyc +0 -0
  44. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_decompositions.cpython-310.pyc +0 -0
  45. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_determinant.cpython-310.pyc +0 -0
  46. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_eigen.cpython-310.pyc +0 -0
  47. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_graph.cpython-310.pyc +0 -0
  48. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_immutable.cpython-310.pyc +0 -0
  49. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_interactions.cpython-310.pyc +0 -0
  50. llmeval-env/lib/python3.10/site-packages/sympy/matrices/tests/__pycache__/test_matrices.cpython-310.pyc +0 -0
llmeval-env/lib/python3.10/site-packages/sympy/calculus/__init__.py ADDED
@@ -0,0 +1,25 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """Calculus-related methods."""
2
+
3
+ from .euler import euler_equations
4
+ from .singularities import (singularities, is_increasing,
5
+ is_strictly_increasing, is_decreasing,
6
+ is_strictly_decreasing, is_monotonic)
7
+ from .finite_diff import finite_diff_weights, apply_finite_diff, differentiate_finite
8
+ from .util import (periodicity, not_empty_in, is_convex,
9
+ stationary_points, minimum, maximum)
10
+ from .accumulationbounds import AccumBounds
11
+
12
+ __all__ = [
13
+ 'euler_equations',
14
+
15
+ 'singularities', 'is_increasing',
16
+ 'is_strictly_increasing', 'is_decreasing',
17
+ 'is_strictly_decreasing', 'is_monotonic',
18
+
19
+ 'finite_diff_weights', 'apply_finite_diff', 'differentiate_finite',
20
+
21
+ 'periodicity', 'not_empty_in', 'is_convex', 'stationary_points',
22
+ 'minimum', 'maximum',
23
+
24
+ 'AccumBounds'
25
+ ]
llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/__init__.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/accumulationbounds.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/euler.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/singularities.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/calculus/__pycache__/util.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/calculus/accumulationbounds.py ADDED
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1
+ from sympy.core import Add, Mul, Pow, S
2
+ from sympy.core.basic import Basic
3
+ from sympy.core.expr import Expr
4
+ from sympy.core.numbers import _sympifyit, oo, zoo
5
+ from sympy.core.relational import is_le, is_lt, is_ge, is_gt
6
+ from sympy.core.sympify import _sympify
7
+ from sympy.functions.elementary.miscellaneous import Min, Max
8
+ from sympy.logic.boolalg import And
9
+ from sympy.multipledispatch import dispatch
10
+ from sympy.series.order import Order
11
+ from sympy.sets.sets import FiniteSet
12
+
13
+
14
+ class AccumulationBounds(Expr):
15
+ r"""An accumulation bounds.
16
+
17
+ # Note AccumulationBounds has an alias: AccumBounds
18
+
19
+ AccumulationBounds represent an interval `[a, b]`, which is always closed
20
+ at the ends. Here `a` and `b` can be any value from extended real numbers.
21
+
22
+ The intended meaning of AccummulationBounds is to give an approximate
23
+ location of the accumulation points of a real function at a limit point.
24
+
25
+ Let `a` and `b` be reals such that `a \le b`.
26
+
27
+ `\left\langle a, b\right\rangle = \{x \in \mathbb{R} \mid a \le x \le b\}`
28
+
29
+ `\left\langle -\infty, b\right\rangle = \{x \in \mathbb{R} \mid x \le b\} \cup \{-\infty, \infty\}`
30
+
31
+ `\left\langle a, \infty \right\rangle = \{x \in \mathbb{R} \mid a \le x\} \cup \{-\infty, \infty\}`
32
+
33
+ `\left\langle -\infty, \infty \right\rangle = \mathbb{R} \cup \{-\infty, \infty\}`
34
+
35
+ ``oo`` and ``-oo`` are added to the second and third definition respectively,
36
+ since if either ``-oo`` or ``oo`` is an argument, then the other one should
37
+ be included (though not as an end point). This is forced, since we have,
38
+ for example, ``1/AccumBounds(0, 1) = AccumBounds(1, oo)``, and the limit at
39
+ `0` is not one-sided. As `x` tends to `0-`, then `1/x \rightarrow -\infty`, so `-\infty`
40
+ should be interpreted as belonging to ``AccumBounds(1, oo)`` though it need
41
+ not appear explicitly.
42
+
43
+ In many cases it suffices to know that the limit set is bounded.
44
+ However, in some other cases more exact information could be useful.
45
+ For example, all accumulation values of `\cos(x) + 1` are non-negative.
46
+ (``AccumBounds(-1, 1) + 1 = AccumBounds(0, 2)``)
47
+
48
+ A AccumulationBounds object is defined to be real AccumulationBounds,
49
+ if its end points are finite reals.
50
+
51
+ Let `X`, `Y` be real AccumulationBounds, then their sum, difference,
52
+ product are defined to be the following sets:
53
+
54
+ `X + Y = \{ x+y \mid x \in X \cap y \in Y\}`
55
+
56
+ `X - Y = \{ x-y \mid x \in X \cap y \in Y\}`
57
+
58
+ `X \times Y = \{ x \times y \mid x \in X \cap y \in Y\}`
59
+
60
+ When an AccumBounds is raised to a negative power, if 0 is contained
61
+ between the bounds then an infinite range is returned, otherwise if an
62
+ endpoint is 0 then a semi-infinite range with consistent sign will be returned.
63
+
64
+ AccumBounds in expressions behave a lot like Intervals but the
65
+ semantics are not necessarily the same. Division (or exponentiation
66
+ to a negative integer power) could be handled with *intervals* by
67
+ returning a union of the results obtained after splitting the
68
+ bounds between negatives and positives, but that is not done with
69
+ AccumBounds. In addition, bounds are assumed to be independent of
70
+ each other; if the same bound is used in more than one place in an
71
+ expression, the result may not be the supremum or infimum of the
72
+ expression (see below). Finally, when a boundary is ``1``,
73
+ exponentiation to the power of ``oo`` yields ``oo``, neither
74
+ ``1`` nor ``nan``.
75
+
76
+ Examples
77
+ ========
78
+
79
+ >>> from sympy import AccumBounds, sin, exp, log, pi, E, S, oo
80
+ >>> from sympy.abc import x
81
+
82
+ >>> AccumBounds(0, 1) + AccumBounds(1, 2)
83
+ AccumBounds(1, 3)
84
+
85
+ >>> AccumBounds(0, 1) - AccumBounds(0, 2)
86
+ AccumBounds(-2, 1)
87
+
88
+ >>> AccumBounds(-2, 3)*AccumBounds(-1, 1)
89
+ AccumBounds(-3, 3)
90
+
91
+ >>> AccumBounds(1, 2)*AccumBounds(3, 5)
92
+ AccumBounds(3, 10)
93
+
94
+ The exponentiation of AccumulationBounds is defined
95
+ as follows:
96
+
97
+ If 0 does not belong to `X` or `n > 0` then
98
+
99
+ `X^n = \{ x^n \mid x \in X\}`
100
+
101
+ >>> AccumBounds(1, 4)**(S(1)/2)
102
+ AccumBounds(1, 2)
103
+
104
+ otherwise, an infinite or semi-infinite result is obtained:
105
+
106
+ >>> 1/AccumBounds(-1, 1)
107
+ AccumBounds(-oo, oo)
108
+ >>> 1/AccumBounds(0, 2)
109
+ AccumBounds(1/2, oo)
110
+ >>> 1/AccumBounds(-oo, 0)
111
+ AccumBounds(-oo, 0)
112
+
113
+ A boundary of 1 will always generate all nonnegatives:
114
+
115
+ >>> AccumBounds(1, 2)**oo
116
+ AccumBounds(0, oo)
117
+ >>> AccumBounds(0, 1)**oo
118
+ AccumBounds(0, oo)
119
+
120
+ If the exponent is itself an AccumulationBounds or is not an
121
+ integer then unevaluated results will be returned unless the base
122
+ values are positive:
123
+
124
+ >>> AccumBounds(2, 3)**AccumBounds(-1, 2)
125
+ AccumBounds(1/3, 9)
126
+ >>> AccumBounds(-2, 3)**AccumBounds(-1, 2)
127
+ AccumBounds(-2, 3)**AccumBounds(-1, 2)
128
+
129
+ >>> AccumBounds(-2, -1)**(S(1)/2)
130
+ sqrt(AccumBounds(-2, -1))
131
+
132
+ Note: `\left\langle a, b\right\rangle^2` is not same as `\left\langle a, b\right\rangle \times \left\langle a, b\right\rangle`
133
+
134
+ >>> AccumBounds(-1, 1)**2
135
+ AccumBounds(0, 1)
136
+
137
+ >>> AccumBounds(1, 3) < 4
138
+ True
139
+
140
+ >>> AccumBounds(1, 3) < -1
141
+ False
142
+
143
+ Some elementary functions can also take AccumulationBounds as input.
144
+ A function `f` evaluated for some real AccumulationBounds `\left\langle a, b \right\rangle`
145
+ is defined as `f(\left\langle a, b\right\rangle) = \{ f(x) \mid a \le x \le b \}`
146
+
147
+ >>> sin(AccumBounds(pi/6, pi/3))
148
+ AccumBounds(1/2, sqrt(3)/2)
149
+
150
+ >>> exp(AccumBounds(0, 1))
151
+ AccumBounds(1, E)
152
+
153
+ >>> log(AccumBounds(1, E))
154
+ AccumBounds(0, 1)
155
+
156
+ Some symbol in an expression can be substituted for a AccumulationBounds
157
+ object. But it does not necessarily evaluate the AccumulationBounds for
158
+ that expression.
159
+
160
+ The same expression can be evaluated to different values depending upon
161
+ the form it is used for substitution since each instance of an
162
+ AccumulationBounds is considered independent. For example:
163
+
164
+ >>> (x**2 + 2*x + 1).subs(x, AccumBounds(-1, 1))
165
+ AccumBounds(-1, 4)
166
+
167
+ >>> ((x + 1)**2).subs(x, AccumBounds(-1, 1))
168
+ AccumBounds(0, 4)
169
+
170
+ References
171
+ ==========
172
+
173
+ .. [1] https://en.wikipedia.org/wiki/Interval_arithmetic
174
+
175
+ .. [2] https://fab.cba.mit.edu/classes/S62.12/docs/Hickey_interval.pdf
176
+
177
+ Notes
178
+ =====
179
+
180
+ Do not use ``AccumulationBounds`` for floating point interval arithmetic
181
+ calculations, use ``mpmath.iv`` instead.
182
+ """
183
+
184
+ is_extended_real = True
185
+ is_number = False
186
+
187
+ def __new__(cls, min, max):
188
+
189
+ min = _sympify(min)
190
+ max = _sympify(max)
191
+
192
+ # Only allow real intervals (use symbols with 'is_extended_real=True').
193
+ if not min.is_extended_real or not max.is_extended_real:
194
+ raise ValueError("Only real AccumulationBounds are supported")
195
+
196
+ if max == min:
197
+ return max
198
+
199
+ # Make sure that the created AccumBounds object will be valid.
200
+ if max.is_number and min.is_number:
201
+ bad = max.is_comparable and min.is_comparable and max < min
202
+ else:
203
+ bad = (max - min).is_extended_negative
204
+ if bad:
205
+ raise ValueError(
206
+ "Lower limit should be smaller than upper limit")
207
+
208
+ return Basic.__new__(cls, min, max)
209
+
210
+ # setting the operation priority
211
+ _op_priority = 11.0
212
+
213
+ def _eval_is_real(self):
214
+ if self.min.is_real and self.max.is_real:
215
+ return True
216
+
217
+ @property
218
+ def min(self):
219
+ """
220
+ Returns the minimum possible value attained by AccumulationBounds
221
+ object.
222
+
223
+ Examples
224
+ ========
225
+
226
+ >>> from sympy import AccumBounds
227
+ >>> AccumBounds(1, 3).min
228
+ 1
229
+
230
+ """
231
+ return self.args[0]
232
+
233
+ @property
234
+ def max(self):
235
+ """
236
+ Returns the maximum possible value attained by AccumulationBounds
237
+ object.
238
+
239
+ Examples
240
+ ========
241
+
242
+ >>> from sympy import AccumBounds
243
+ >>> AccumBounds(1, 3).max
244
+ 3
245
+
246
+ """
247
+ return self.args[1]
248
+
249
+ @property
250
+ def delta(self):
251
+ """
252
+ Returns the difference of maximum possible value attained by
253
+ AccumulationBounds object and minimum possible value attained
254
+ by AccumulationBounds object.
255
+
256
+ Examples
257
+ ========
258
+
259
+ >>> from sympy import AccumBounds
260
+ >>> AccumBounds(1, 3).delta
261
+ 2
262
+
263
+ """
264
+ return self.max - self.min
265
+
266
+ @property
267
+ def mid(self):
268
+ """
269
+ Returns the mean of maximum possible value attained by
270
+ AccumulationBounds object and minimum possible value
271
+ attained by AccumulationBounds object.
272
+
273
+ Examples
274
+ ========
275
+
276
+ >>> from sympy import AccumBounds
277
+ >>> AccumBounds(1, 3).mid
278
+ 2
279
+
280
+ """
281
+ return (self.min + self.max) / 2
282
+
283
+ @_sympifyit('other', NotImplemented)
284
+ def _eval_power(self, other):
285
+ return self.__pow__(other)
286
+
287
+ @_sympifyit('other', NotImplemented)
288
+ def __add__(self, other):
289
+ if isinstance(other, Expr):
290
+ if isinstance(other, AccumBounds):
291
+ return AccumBounds(
292
+ Add(self.min, other.min),
293
+ Add(self.max, other.max))
294
+ if other is S.Infinity and self.min is S.NegativeInfinity or \
295
+ other is S.NegativeInfinity and self.max is S.Infinity:
296
+ return AccumBounds(-oo, oo)
297
+ elif other.is_extended_real:
298
+ if self.min is S.NegativeInfinity and self.max is S.Infinity:
299
+ return AccumBounds(-oo, oo)
300
+ elif self.min is S.NegativeInfinity:
301
+ return AccumBounds(-oo, self.max + other)
302
+ elif self.max is S.Infinity:
303
+ return AccumBounds(self.min + other, oo)
304
+ else:
305
+ return AccumBounds(Add(self.min, other), Add(self.max, other))
306
+ return Add(self, other, evaluate=False)
307
+ return NotImplemented
308
+
309
+ __radd__ = __add__
310
+
311
+ def __neg__(self):
312
+ return AccumBounds(-self.max, -self.min)
313
+
314
+ @_sympifyit('other', NotImplemented)
315
+ def __sub__(self, other):
316
+ if isinstance(other, Expr):
317
+ if isinstance(other, AccumBounds):
318
+ return AccumBounds(
319
+ Add(self.min, -other.max),
320
+ Add(self.max, -other.min))
321
+ if other is S.NegativeInfinity and self.min is S.NegativeInfinity or \
322
+ other is S.Infinity and self.max is S.Infinity:
323
+ return AccumBounds(-oo, oo)
324
+ elif other.is_extended_real:
325
+ if self.min is S.NegativeInfinity and self.max is S.Infinity:
326
+ return AccumBounds(-oo, oo)
327
+ elif self.min is S.NegativeInfinity:
328
+ return AccumBounds(-oo, self.max - other)
329
+ elif self.max is S.Infinity:
330
+ return AccumBounds(self.min - other, oo)
331
+ else:
332
+ return AccumBounds(
333
+ Add(self.min, -other),
334
+ Add(self.max, -other))
335
+ return Add(self, -other, evaluate=False)
336
+ return NotImplemented
337
+
338
+ @_sympifyit('other', NotImplemented)
339
+ def __rsub__(self, other):
340
+ return self.__neg__() + other
341
+
342
+ @_sympifyit('other', NotImplemented)
343
+ def __mul__(self, other):
344
+ if self.args == (-oo, oo):
345
+ return self
346
+ if isinstance(other, Expr):
347
+ if isinstance(other, AccumBounds):
348
+ if other.args == (-oo, oo):
349
+ return other
350
+ v = set()
351
+ for a in self.args:
352
+ vi = other*a
353
+ for i in vi.args or (vi,):
354
+ v.add(i)
355
+ return AccumBounds(Min(*v), Max(*v))
356
+ if other is S.Infinity:
357
+ if self.min.is_zero:
358
+ return AccumBounds(0, oo)
359
+ if self.max.is_zero:
360
+ return AccumBounds(-oo, 0)
361
+ if other is S.NegativeInfinity:
362
+ if self.min.is_zero:
363
+ return AccumBounds(-oo, 0)
364
+ if self.max.is_zero:
365
+ return AccumBounds(0, oo)
366
+ if other.is_extended_real:
367
+ if other.is_zero:
368
+ if self.max is S.Infinity:
369
+ return AccumBounds(0, oo)
370
+ if self.min is S.NegativeInfinity:
371
+ return AccumBounds(-oo, 0)
372
+ return S.Zero
373
+ if other.is_extended_positive:
374
+ return AccumBounds(
375
+ Mul(self.min, other),
376
+ Mul(self.max, other))
377
+ elif other.is_extended_negative:
378
+ return AccumBounds(
379
+ Mul(self.max, other),
380
+ Mul(self.min, other))
381
+ if isinstance(other, Order):
382
+ return other
383
+ return Mul(self, other, evaluate=False)
384
+ return NotImplemented
385
+
386
+ __rmul__ = __mul__
387
+
388
+ @_sympifyit('other', NotImplemented)
389
+ def __truediv__(self, other):
390
+ if isinstance(other, Expr):
391
+ if isinstance(other, AccumBounds):
392
+ if other.min.is_positive or other.max.is_negative:
393
+ return self * AccumBounds(1/other.max, 1/other.min)
394
+
395
+ if (self.min.is_extended_nonpositive and self.max.is_extended_nonnegative and
396
+ other.min.is_extended_nonpositive and other.max.is_extended_nonnegative):
397
+ if self.min.is_zero and other.min.is_zero:
398
+ return AccumBounds(0, oo)
399
+ if self.max.is_zero and other.min.is_zero:
400
+ return AccumBounds(-oo, 0)
401
+ return AccumBounds(-oo, oo)
402
+
403
+ if self.max.is_extended_negative:
404
+ if other.min.is_extended_negative:
405
+ if other.max.is_zero:
406
+ return AccumBounds(self.max / other.min, oo)
407
+ if other.max.is_extended_positive:
408
+ # if we were dealing with intervals we would return
409
+ # Union(Interval(-oo, self.max/other.max),
410
+ # Interval(self.max/other.min, oo))
411
+ return AccumBounds(-oo, oo)
412
+
413
+ if other.min.is_zero and other.max.is_extended_positive:
414
+ return AccumBounds(-oo, self.max / other.max)
415
+
416
+ if self.min.is_extended_positive:
417
+ if other.min.is_extended_negative:
418
+ if other.max.is_zero:
419
+ return AccumBounds(-oo, self.min / other.min)
420
+ if other.max.is_extended_positive:
421
+ # if we were dealing with intervals we would return
422
+ # Union(Interval(-oo, self.min/other.min),
423
+ # Interval(self.min/other.max, oo))
424
+ return AccumBounds(-oo, oo)
425
+
426
+ if other.min.is_zero and other.max.is_extended_positive:
427
+ return AccumBounds(self.min / other.max, oo)
428
+
429
+ elif other.is_extended_real:
430
+ if other in (S.Infinity, S.NegativeInfinity):
431
+ if self == AccumBounds(-oo, oo):
432
+ return AccumBounds(-oo, oo)
433
+ if self.max is S.Infinity:
434
+ return AccumBounds(Min(0, other), Max(0, other))
435
+ if self.min is S.NegativeInfinity:
436
+ return AccumBounds(Min(0, -other), Max(0, -other))
437
+ if other.is_extended_positive:
438
+ return AccumBounds(self.min / other, self.max / other)
439
+ elif other.is_extended_negative:
440
+ return AccumBounds(self.max / other, self.min / other)
441
+ if (1 / other) is S.ComplexInfinity:
442
+ return Mul(self, 1 / other, evaluate=False)
443
+ else:
444
+ return Mul(self, 1 / other)
445
+
446
+ return NotImplemented
447
+
448
+ @_sympifyit('other', NotImplemented)
449
+ def __rtruediv__(self, other):
450
+ if isinstance(other, Expr):
451
+ if other.is_extended_real:
452
+ if other.is_zero:
453
+ return S.Zero
454
+ if (self.min.is_extended_nonpositive and self.max.is_extended_nonnegative):
455
+ if self.min.is_zero:
456
+ if other.is_extended_positive:
457
+ return AccumBounds(Mul(other, 1 / self.max), oo)
458
+ if other.is_extended_negative:
459
+ return AccumBounds(-oo, Mul(other, 1 / self.max))
460
+ if self.max.is_zero:
461
+ if other.is_extended_positive:
462
+ return AccumBounds(-oo, Mul(other, 1 / self.min))
463
+ if other.is_extended_negative:
464
+ return AccumBounds(Mul(other, 1 / self.min), oo)
465
+ return AccumBounds(-oo, oo)
466
+ else:
467
+ return AccumBounds(Min(other / self.min, other / self.max),
468
+ Max(other / self.min, other / self.max))
469
+ return Mul(other, 1 / self, evaluate=False)
470
+ else:
471
+ return NotImplemented
472
+
473
+ @_sympifyit('other', NotImplemented)
474
+ def __pow__(self, other):
475
+ if isinstance(other, Expr):
476
+ if other is S.Infinity:
477
+ if self.min.is_extended_nonnegative:
478
+ if self.max < 1:
479
+ return S.Zero
480
+ if self.min > 1:
481
+ return S.Infinity
482
+ return AccumBounds(0, oo)
483
+ elif self.max.is_extended_negative:
484
+ if self.min > -1:
485
+ return S.Zero
486
+ if self.max < -1:
487
+ return zoo
488
+ return S.NaN
489
+ else:
490
+ if self.min > -1:
491
+ if self.max < 1:
492
+ return S.Zero
493
+ return AccumBounds(0, oo)
494
+ return AccumBounds(-oo, oo)
495
+
496
+ if other is S.NegativeInfinity:
497
+ return (1/self)**oo
498
+
499
+ # generically true
500
+ if (self.max - self.min).is_nonnegative:
501
+ # well defined
502
+ if self.min.is_nonnegative:
503
+ # no 0 to worry about
504
+ if other.is_nonnegative:
505
+ # no infinity to worry about
506
+ return self.func(self.min**other, self.max**other)
507
+
508
+ if other.is_zero:
509
+ return S.One # x**0 = 1
510
+
511
+ if other.is_Integer or other.is_integer:
512
+ if self.min.is_extended_positive:
513
+ return AccumBounds(
514
+ Min(self.min**other, self.max**other),
515
+ Max(self.min**other, self.max**other))
516
+ elif self.max.is_extended_negative:
517
+ return AccumBounds(
518
+ Min(self.max**other, self.min**other),
519
+ Max(self.max**other, self.min**other))
520
+
521
+ if other % 2 == 0:
522
+ if other.is_extended_negative:
523
+ if self.min.is_zero:
524
+ return AccumBounds(self.max**other, oo)
525
+ if self.max.is_zero:
526
+ return AccumBounds(self.min**other, oo)
527
+ return (1/self)**(-other)
528
+ return AccumBounds(
529
+ S.Zero, Max(self.min**other, self.max**other))
530
+ elif other % 2 == 1:
531
+ if other.is_extended_negative:
532
+ if self.min.is_zero:
533
+ return AccumBounds(self.max**other, oo)
534
+ if self.max.is_zero:
535
+ return AccumBounds(-oo, self.min**other)
536
+ return (1/self)**(-other)
537
+ return AccumBounds(self.min**other, self.max**other)
538
+
539
+ # non-integer exponent
540
+ # 0**neg or neg**frac yields complex
541
+ if (other.is_number or other.is_rational) and (
542
+ self.min.is_extended_nonnegative or (
543
+ other.is_extended_nonnegative and
544
+ self.min.is_extended_nonnegative)):
545
+ num, den = other.as_numer_denom()
546
+ if num is S.One:
547
+ return AccumBounds(*[i**(1/den) for i in self.args])
548
+
549
+ elif den is not S.One: # e.g. if other is not Float
550
+ return (self**num)**(1/den) # ok for non-negative base
551
+
552
+ if isinstance(other, AccumBounds):
553
+ if (self.min.is_extended_positive or
554
+ self.min.is_extended_nonnegative and
555
+ other.min.is_extended_nonnegative):
556
+ p = [self**i for i in other.args]
557
+ if not any(i.is_Pow for i in p):
558
+ a = [j for i in p for j in i.args or (i,)]
559
+ try:
560
+ return self.func(min(a), max(a))
561
+ except TypeError: # can't sort
562
+ pass
563
+
564
+ return Pow(self, other, evaluate=False)
565
+
566
+ return NotImplemented
567
+
568
+ @_sympifyit('other', NotImplemented)
569
+ def __rpow__(self, other):
570
+ if other.is_real and other.is_extended_nonnegative and (
571
+ self.max - self.min).is_extended_positive:
572
+ if other is S.One:
573
+ return S.One
574
+ if other.is_extended_positive:
575
+ a, b = [other**i for i in self.args]
576
+ if min(a, b) != a:
577
+ a, b = b, a
578
+ return self.func(a, b)
579
+ if other.is_zero:
580
+ if self.min.is_zero:
581
+ return self.func(0, 1)
582
+ if self.min.is_extended_positive:
583
+ return S.Zero
584
+
585
+ return Pow(other, self, evaluate=False)
586
+
587
+ def __abs__(self):
588
+ if self.max.is_extended_negative:
589
+ return self.__neg__()
590
+ elif self.min.is_extended_negative:
591
+ return AccumBounds(S.Zero, Max(abs(self.min), self.max))
592
+ else:
593
+ return self
594
+
595
+
596
+ def __contains__(self, other):
597
+ """
598
+ Returns ``True`` if other is contained in self, where other
599
+ belongs to extended real numbers, ``False`` if not contained,
600
+ otherwise TypeError is raised.
601
+
602
+ Examples
603
+ ========
604
+
605
+ >>> from sympy import AccumBounds, oo
606
+ >>> 1 in AccumBounds(-1, 3)
607
+ True
608
+
609
+ -oo and oo go together as limits (in AccumulationBounds).
610
+
611
+ >>> -oo in AccumBounds(1, oo)
612
+ True
613
+
614
+ >>> oo in AccumBounds(-oo, 0)
615
+ True
616
+
617
+ """
618
+ other = _sympify(other)
619
+
620
+ if other in (S.Infinity, S.NegativeInfinity):
621
+ if self.min is S.NegativeInfinity or self.max is S.Infinity:
622
+ return True
623
+ return False
624
+
625
+ rv = And(self.min <= other, self.max >= other)
626
+ if rv not in (True, False):
627
+ raise TypeError("input failed to evaluate")
628
+ return rv
629
+
630
+ def intersection(self, other):
631
+ """
632
+ Returns the intersection of 'self' and 'other'.
633
+ Here other can be an instance of :py:class:`~.FiniteSet` or AccumulationBounds.
634
+
635
+ Parameters
636
+ ==========
637
+
638
+ other : AccumulationBounds
639
+ Another AccumulationBounds object with which the intersection
640
+ has to be computed.
641
+
642
+ Returns
643
+ =======
644
+
645
+ AccumulationBounds
646
+ Intersection of ``self`` and ``other``.
647
+
648
+ Examples
649
+ ========
650
+
651
+ >>> from sympy import AccumBounds, FiniteSet
652
+ >>> AccumBounds(1, 3).intersection(AccumBounds(2, 4))
653
+ AccumBounds(2, 3)
654
+
655
+ >>> AccumBounds(1, 3).intersection(AccumBounds(4, 6))
656
+ EmptySet
657
+
658
+ >>> AccumBounds(1, 4).intersection(FiniteSet(1, 2, 5))
659
+ {1, 2}
660
+
661
+ """
662
+ if not isinstance(other, (AccumBounds, FiniteSet)):
663
+ raise TypeError(
664
+ "Input must be AccumulationBounds or FiniteSet object")
665
+
666
+ if isinstance(other, FiniteSet):
667
+ fin_set = S.EmptySet
668
+ for i in other:
669
+ if i in self:
670
+ fin_set = fin_set + FiniteSet(i)
671
+ return fin_set
672
+
673
+ if self.max < other.min or self.min > other.max:
674
+ return S.EmptySet
675
+
676
+ if self.min <= other.min:
677
+ if self.max <= other.max:
678
+ return AccumBounds(other.min, self.max)
679
+ if self.max > other.max:
680
+ return other
681
+
682
+ if other.min <= self.min:
683
+ if other.max < self.max:
684
+ return AccumBounds(self.min, other.max)
685
+ if other.max > self.max:
686
+ return self
687
+
688
+ def union(self, other):
689
+ # TODO : Devise a better method for Union of AccumBounds
690
+ # this method is not actually correct and
691
+ # can be made better
692
+ if not isinstance(other, AccumBounds):
693
+ raise TypeError(
694
+ "Input must be AccumulationBounds or FiniteSet object")
695
+
696
+ if self.min <= other.min and self.max >= other.min:
697
+ return AccumBounds(self.min, Max(self.max, other.max))
698
+
699
+ if other.min <= self.min and other.max >= self.min:
700
+ return AccumBounds(other.min, Max(self.max, other.max))
701
+
702
+
703
+ @dispatch(AccumulationBounds, AccumulationBounds) # type: ignore # noqa:F811
704
+ def _eval_is_le(lhs, rhs): # noqa:F811
705
+ if is_le(lhs.max, rhs.min):
706
+ return True
707
+ if is_gt(lhs.min, rhs.max):
708
+ return False
709
+
710
+
711
+ @dispatch(AccumulationBounds, Basic) # type: ignore # noqa:F811
712
+ def _eval_is_le(lhs, rhs): # noqa: F811
713
+
714
+ """
715
+ Returns ``True `` if range of values attained by ``lhs`` AccumulationBounds
716
+ object is greater than the range of values attained by ``rhs``,
717
+ where ``rhs`` may be any value of type AccumulationBounds object or
718
+ extended real number value, ``False`` if ``rhs`` satisfies
719
+ the same property, else an unevaluated :py:class:`~.Relational`.
720
+
721
+ Examples
722
+ ========
723
+
724
+ >>> from sympy import AccumBounds, oo
725
+ >>> AccumBounds(1, 3) > AccumBounds(4, oo)
726
+ False
727
+ >>> AccumBounds(1, 4) > AccumBounds(3, 4)
728
+ AccumBounds(1, 4) > AccumBounds(3, 4)
729
+ >>> AccumBounds(1, oo) > -1
730
+ True
731
+
732
+ """
733
+ if not rhs.is_extended_real:
734
+ raise TypeError(
735
+ "Invalid comparison of %s %s" %
736
+ (type(rhs), rhs))
737
+ elif rhs.is_comparable:
738
+ if is_le(lhs.max, rhs):
739
+ return True
740
+ if is_gt(lhs.min, rhs):
741
+ return False
742
+
743
+
744
+ @dispatch(AccumulationBounds, AccumulationBounds)
745
+ def _eval_is_ge(lhs, rhs): # noqa:F811
746
+ if is_ge(lhs.min, rhs.max):
747
+ return True
748
+ if is_lt(lhs.max, rhs.min):
749
+ return False
750
+
751
+
752
+ @dispatch(AccumulationBounds, Expr) # type:ignore
753
+ def _eval_is_ge(lhs, rhs): # noqa: F811
754
+ """
755
+ Returns ``True`` if range of values attained by ``lhs`` AccumulationBounds
756
+ object is less that the range of values attained by ``rhs``, where
757
+ other may be any value of type AccumulationBounds object or extended
758
+ real number value, ``False`` if ``rhs`` satisfies the same
759
+ property, else an unevaluated :py:class:`~.Relational`.
760
+
761
+ Examples
762
+ ========
763
+
764
+ >>> from sympy import AccumBounds, oo
765
+ >>> AccumBounds(1, 3) >= AccumBounds(4, oo)
766
+ False
767
+ >>> AccumBounds(1, 4) >= AccumBounds(3, 4)
768
+ AccumBounds(1, 4) >= AccumBounds(3, 4)
769
+ >>> AccumBounds(1, oo) >= 1
770
+ True
771
+ """
772
+
773
+ if not rhs.is_extended_real:
774
+ raise TypeError(
775
+ "Invalid comparison of %s %s" %
776
+ (type(rhs), rhs))
777
+ elif rhs.is_comparable:
778
+ if is_ge(lhs.min, rhs):
779
+ return True
780
+ if is_lt(lhs.max, rhs):
781
+ return False
782
+
783
+
784
+ @dispatch(Expr, AccumulationBounds) # type:ignore
785
+ def _eval_is_ge(lhs, rhs): # noqa:F811
786
+ if not lhs.is_extended_real:
787
+ raise TypeError(
788
+ "Invalid comparison of %s %s" %
789
+ (type(lhs), lhs))
790
+ elif lhs.is_comparable:
791
+ if is_le(rhs.max, lhs):
792
+ return True
793
+ if is_gt(rhs.min, lhs):
794
+ return False
795
+
796
+
797
+ @dispatch(AccumulationBounds, AccumulationBounds) # type:ignore
798
+ def _eval_is_ge(lhs, rhs): # noqa:F811
799
+ if is_ge(lhs.min, rhs.max):
800
+ return True
801
+ if is_lt(lhs.max, rhs.min):
802
+ return False
803
+
804
+ # setting an alias for AccumulationBounds
805
+ AccumBounds = AccumulationBounds
llmeval-env/lib/python3.10/site-packages/sympy/calculus/euler.py ADDED
@@ -0,0 +1,108 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ This module implements a method to find
3
+ Euler-Lagrange Equations for given Lagrangian.
4
+ """
5
+ from itertools import combinations_with_replacement
6
+ from sympy.core.function import (Derivative, Function, diff)
7
+ from sympy.core.relational import Eq
8
+ from sympy.core.singleton import S
9
+ from sympy.core.symbol import Symbol
10
+ from sympy.core.sympify import sympify
11
+ from sympy.utilities.iterables import iterable
12
+
13
+
14
+ def euler_equations(L, funcs=(), vars=()):
15
+ r"""
16
+ Find the Euler-Lagrange equations [1]_ for a given Lagrangian.
17
+
18
+ Parameters
19
+ ==========
20
+
21
+ L : Expr
22
+ The Lagrangian that should be a function of the functions listed
23
+ in the second argument and their derivatives.
24
+
25
+ For example, in the case of two functions $f(x,y)$, $g(x,y)$ and
26
+ two independent variables $x$, $y$ the Lagrangian has the form:
27
+
28
+ .. math:: L\left(f(x,y),g(x,y),\frac{\partial f(x,y)}{\partial x},
29
+ \frac{\partial f(x,y)}{\partial y},
30
+ \frac{\partial g(x,y)}{\partial x},
31
+ \frac{\partial g(x,y)}{\partial y},x,y\right)
32
+
33
+ In many cases it is not necessary to provide anything, except the
34
+ Lagrangian, it will be auto-detected (and an error raised if this
35
+ cannot be done).
36
+
37
+ funcs : Function or an iterable of Functions
38
+ The functions that the Lagrangian depends on. The Euler equations
39
+ are differential equations for each of these functions.
40
+
41
+ vars : Symbol or an iterable of Symbols
42
+ The Symbols that are the independent variables of the functions.
43
+
44
+ Returns
45
+ =======
46
+
47
+ eqns : list of Eq
48
+ The list of differential equations, one for each function.
49
+
50
+ Examples
51
+ ========
52
+
53
+ >>> from sympy import euler_equations, Symbol, Function
54
+ >>> x = Function('x')
55
+ >>> t = Symbol('t')
56
+ >>> L = (x(t).diff(t))**2/2 - x(t)**2/2
57
+ >>> euler_equations(L, x(t), t)
58
+ [Eq(-x(t) - Derivative(x(t), (t, 2)), 0)]
59
+ >>> u = Function('u')
60
+ >>> x = Symbol('x')
61
+ >>> L = (u(t, x).diff(t))**2/2 - (u(t, x).diff(x))**2/2
62
+ >>> euler_equations(L, u(t, x), [t, x])
63
+ [Eq(-Derivative(u(t, x), (t, 2)) + Derivative(u(t, x), (x, 2)), 0)]
64
+
65
+ References
66
+ ==========
67
+
68
+ .. [1] https://en.wikipedia.org/wiki/Euler%E2%80%93Lagrange_equation
69
+
70
+ """
71
+
72
+ funcs = tuple(funcs) if iterable(funcs) else (funcs,)
73
+
74
+ if not funcs:
75
+ funcs = tuple(L.atoms(Function))
76
+ else:
77
+ for f in funcs:
78
+ if not isinstance(f, Function):
79
+ raise TypeError('Function expected, got: %s' % f)
80
+
81
+ vars = tuple(vars) if iterable(vars) else (vars,)
82
+
83
+ if not vars:
84
+ vars = funcs[0].args
85
+ else:
86
+ vars = tuple(sympify(var) for var in vars)
87
+
88
+ if not all(isinstance(v, Symbol) for v in vars):
89
+ raise TypeError('Variables are not symbols, got %s' % vars)
90
+
91
+ for f in funcs:
92
+ if not vars == f.args:
93
+ raise ValueError("Variables %s do not match args: %s" % (vars, f))
94
+
95
+ order = max([len(d.variables) for d in L.atoms(Derivative)
96
+ if d.expr in funcs] + [0])
97
+
98
+ eqns = []
99
+ for f in funcs:
100
+ eq = diff(L, f)
101
+ for i in range(1, order + 1):
102
+ for p in combinations_with_replacement(vars, i):
103
+ eq = eq + S.NegativeOne**i*diff(L, diff(f, *p), *p)
104
+ new_eq = Eq(eq, 0)
105
+ if isinstance(new_eq, Eq):
106
+ eqns.append(new_eq)
107
+
108
+ return eqns
llmeval-env/lib/python3.10/site-packages/sympy/calculus/finite_diff.py ADDED
@@ -0,0 +1,476 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ Finite difference weights
3
+ =========================
4
+
5
+ This module implements an algorithm for efficient generation of finite
6
+ difference weights for ordinary differentials of functions for
7
+ derivatives from 0 (interpolation) up to arbitrary order.
8
+
9
+ The core algorithm is provided in the finite difference weight generating
10
+ function (``finite_diff_weights``), and two convenience functions are provided
11
+ for:
12
+
13
+ - estimating a derivative (or interpolate) directly from a series of points
14
+ is also provided (``apply_finite_diff``).
15
+ - differentiating by using finite difference approximations
16
+ (``differentiate_finite``).
17
+
18
+ """
19
+
20
+ from sympy.core.function import Derivative
21
+ from sympy.core.singleton import S
22
+ from sympy.core.function import Subs
23
+ from sympy.core.traversal import preorder_traversal
24
+ from sympy.utilities.exceptions import sympy_deprecation_warning
25
+ from sympy.utilities.iterables import iterable
26
+
27
+
28
+
29
+ def finite_diff_weights(order, x_list, x0=S.One):
30
+ """
31
+ Calculates the finite difference weights for an arbitrarily spaced
32
+ one-dimensional grid (``x_list``) for derivatives at ``x0`` of order
33
+ 0, 1, ..., up to ``order`` using a recursive formula. Order of accuracy
34
+ is at least ``len(x_list) - order``, if ``x_list`` is defined correctly.
35
+
36
+ Parameters
37
+ ==========
38
+
39
+ order: int
40
+ Up to what derivative order weights should be calculated.
41
+ 0 corresponds to interpolation.
42
+ x_list: sequence
43
+ Sequence of (unique) values for the independent variable.
44
+ It is useful (but not necessary) to order ``x_list`` from
45
+ nearest to furthest from ``x0``; see examples below.
46
+ x0: Number or Symbol
47
+ Root or value of the independent variable for which the finite
48
+ difference weights should be generated. Default is ``S.One``.
49
+
50
+ Returns
51
+ =======
52
+
53
+ list
54
+ A list of sublists, each corresponding to coefficients for
55
+ increasing derivative order, and each containing lists of
56
+ coefficients for increasing subsets of x_list.
57
+
58
+ Examples
59
+ ========
60
+
61
+ >>> from sympy import finite_diff_weights, S
62
+ >>> res = finite_diff_weights(1, [-S(1)/2, S(1)/2, S(3)/2, S(5)/2], 0)
63
+ >>> res
64
+ [[[1, 0, 0, 0],
65
+ [1/2, 1/2, 0, 0],
66
+ [3/8, 3/4, -1/8, 0],
67
+ [5/16, 15/16, -5/16, 1/16]],
68
+ [[0, 0, 0, 0],
69
+ [-1, 1, 0, 0],
70
+ [-1, 1, 0, 0],
71
+ [-23/24, 7/8, 1/8, -1/24]]]
72
+ >>> res[0][-1] # FD weights for 0th derivative, using full x_list
73
+ [5/16, 15/16, -5/16, 1/16]
74
+ >>> res[1][-1] # FD weights for 1st derivative
75
+ [-23/24, 7/8, 1/8, -1/24]
76
+ >>> res[1][-2] # FD weights for 1st derivative, using x_list[:-1]
77
+ [-1, 1, 0, 0]
78
+ >>> res[1][-1][0] # FD weight for 1st deriv. for x_list[0]
79
+ -23/24
80
+ >>> res[1][-1][1] # FD weight for 1st deriv. for x_list[1], etc.
81
+ 7/8
82
+
83
+ Each sublist contains the most accurate formula at the end.
84
+ Note, that in the above example ``res[1][1]`` is the same as ``res[1][2]``.
85
+ Since res[1][2] has an order of accuracy of
86
+ ``len(x_list[:3]) - order = 3 - 1 = 2``, the same is true for ``res[1][1]``!
87
+
88
+ >>> res = finite_diff_weights(1, [S(0), S(1), -S(1), S(2), -S(2)], 0)[1]
89
+ >>> res
90
+ [[0, 0, 0, 0, 0],
91
+ [-1, 1, 0, 0, 0],
92
+ [0, 1/2, -1/2, 0, 0],
93
+ [-1/2, 1, -1/3, -1/6, 0],
94
+ [0, 2/3, -2/3, -1/12, 1/12]]
95
+ >>> res[0] # no approximation possible, using x_list[0] only
96
+ [0, 0, 0, 0, 0]
97
+ >>> res[1] # classic forward step approximation
98
+ [-1, 1, 0, 0, 0]
99
+ >>> res[2] # classic centered approximation
100
+ [0, 1/2, -1/2, 0, 0]
101
+ >>> res[3:] # higher order approximations
102
+ [[-1/2, 1, -1/3, -1/6, 0], [0, 2/3, -2/3, -1/12, 1/12]]
103
+
104
+ Let us compare this to a differently defined ``x_list``. Pay attention to
105
+ ``foo[i][k]`` corresponding to the gridpoint defined by ``x_list[k]``.
106
+
107
+ >>> foo = finite_diff_weights(1, [-S(2), -S(1), S(0), S(1), S(2)], 0)[1]
108
+ >>> foo
109
+ [[0, 0, 0, 0, 0],
110
+ [-1, 1, 0, 0, 0],
111
+ [1/2, -2, 3/2, 0, 0],
112
+ [1/6, -1, 1/2, 1/3, 0],
113
+ [1/12, -2/3, 0, 2/3, -1/12]]
114
+ >>> foo[1] # not the same and of lower accuracy as res[1]!
115
+ [-1, 1, 0, 0, 0]
116
+ >>> foo[2] # classic double backward step approximation
117
+ [1/2, -2, 3/2, 0, 0]
118
+ >>> foo[4] # the same as res[4]
119
+ [1/12, -2/3, 0, 2/3, -1/12]
120
+
121
+ Note that, unless you plan on using approximations based on subsets of
122
+ ``x_list``, the order of gridpoints does not matter.
123
+
124
+ The capability to generate weights at arbitrary points can be
125
+ used e.g. to minimize Runge's phenomenon by using Chebyshev nodes:
126
+
127
+ >>> from sympy import cos, symbols, pi, simplify
128
+ >>> N, (h, x) = 4, symbols('h x')
129
+ >>> x_list = [x+h*cos(i*pi/(N)) for i in range(N,-1,-1)] # chebyshev nodes
130
+ >>> print(x_list)
131
+ [-h + x, -sqrt(2)*h/2 + x, x, sqrt(2)*h/2 + x, h + x]
132
+ >>> mycoeffs = finite_diff_weights(1, x_list, 0)[1][4]
133
+ >>> [simplify(c) for c in mycoeffs] #doctest: +NORMALIZE_WHITESPACE
134
+ [(h**3/2 + h**2*x - 3*h*x**2 - 4*x**3)/h**4,
135
+ (-sqrt(2)*h**3 - 4*h**2*x + 3*sqrt(2)*h*x**2 + 8*x**3)/h**4,
136
+ (6*h**2*x - 8*x**3)/h**4,
137
+ (sqrt(2)*h**3 - 4*h**2*x - 3*sqrt(2)*h*x**2 + 8*x**3)/h**4,
138
+ (-h**3/2 + h**2*x + 3*h*x**2 - 4*x**3)/h**4]
139
+
140
+ Notes
141
+ =====
142
+
143
+ If weights for a finite difference approximation of 3rd order
144
+ derivative is wanted, weights for 0th, 1st and 2nd order are
145
+ calculated "for free", so are formulae using subsets of ``x_list``.
146
+ This is something one can take advantage of to save computational cost.
147
+ Be aware that one should define ``x_list`` from nearest to furthest from
148
+ ``x0``. If not, subsets of ``x_list`` will yield poorer approximations,
149
+ which might not grand an order of accuracy of ``len(x_list) - order``.
150
+
151
+ See also
152
+ ========
153
+
154
+ sympy.calculus.finite_diff.apply_finite_diff
155
+
156
+ References
157
+ ==========
158
+
159
+ .. [1] Generation of Finite Difference Formulas on Arbitrarily Spaced
160
+ Grids, Bengt Fornberg; Mathematics of computation; 51; 184;
161
+ (1988); 699-706; doi:10.1090/S0025-5718-1988-0935077-0
162
+
163
+ """
164
+ # The notation below closely corresponds to the one used in the paper.
165
+ order = S(order)
166
+ if not order.is_number:
167
+ raise ValueError("Cannot handle symbolic order.")
168
+ if order < 0:
169
+ raise ValueError("Negative derivative order illegal.")
170
+ if int(order) != order:
171
+ raise ValueError("Non-integer order illegal")
172
+ M = order
173
+ N = len(x_list) - 1
174
+ delta = [[[0 for nu in range(N+1)] for n in range(N+1)] for
175
+ m in range(M+1)]
176
+ delta[0][0][0] = S.One
177
+ c1 = S.One
178
+ for n in range(1, N+1):
179
+ c2 = S.One
180
+ for nu in range(n):
181
+ c3 = x_list[n] - x_list[nu]
182
+ c2 = c2 * c3
183
+ if n <= M:
184
+ delta[n][n-1][nu] = 0
185
+ for m in range(min(n, M)+1):
186
+ delta[m][n][nu] = (x_list[n]-x0)*delta[m][n-1][nu] -\
187
+ m*delta[m-1][n-1][nu]
188
+ delta[m][n][nu] /= c3
189
+ for m in range(min(n, M)+1):
190
+ delta[m][n][n] = c1/c2*(m*delta[m-1][n-1][n-1] -
191
+ (x_list[n-1]-x0)*delta[m][n-1][n-1])
192
+ c1 = c2
193
+ return delta
194
+
195
+
196
+ def apply_finite_diff(order, x_list, y_list, x0=S.Zero):
197
+ """
198
+ Calculates the finite difference approximation of
199
+ the derivative of requested order at ``x0`` from points
200
+ provided in ``x_list`` and ``y_list``.
201
+
202
+ Parameters
203
+ ==========
204
+
205
+ order: int
206
+ order of derivative to approximate. 0 corresponds to interpolation.
207
+ x_list: sequence
208
+ Sequence of (unique) values for the independent variable.
209
+ y_list: sequence
210
+ The function value at corresponding values for the independent
211
+ variable in x_list.
212
+ x0: Number or Symbol
213
+ At what value of the independent variable the derivative should be
214
+ evaluated. Defaults to 0.
215
+
216
+ Returns
217
+ =======
218
+
219
+ sympy.core.add.Add or sympy.core.numbers.Number
220
+ The finite difference expression approximating the requested
221
+ derivative order at ``x0``.
222
+
223
+ Examples
224
+ ========
225
+
226
+ >>> from sympy import apply_finite_diff
227
+ >>> cube = lambda arg: (1.0*arg)**3
228
+ >>> xlist = range(-3,3+1)
229
+ >>> apply_finite_diff(2, xlist, map(cube, xlist), 2) - 12 # doctest: +SKIP
230
+ -3.55271367880050e-15
231
+
232
+ we see that the example above only contain rounding errors.
233
+ apply_finite_diff can also be used on more abstract objects:
234
+
235
+ >>> from sympy import IndexedBase, Idx
236
+ >>> x, y = map(IndexedBase, 'xy')
237
+ >>> i = Idx('i')
238
+ >>> x_list, y_list = zip(*[(x[i+j], y[i+j]) for j in range(-1,2)])
239
+ >>> apply_finite_diff(1, x_list, y_list, x[i])
240
+ ((x[i + 1] - x[i])/(-x[i - 1] + x[i]) - 1)*y[i]/(x[i + 1] - x[i]) -
241
+ (x[i + 1] - x[i])*y[i - 1]/((x[i + 1] - x[i - 1])*(-x[i - 1] + x[i])) +
242
+ (-x[i - 1] + x[i])*y[i + 1]/((x[i + 1] - x[i - 1])*(x[i + 1] - x[i]))
243
+
244
+ Notes
245
+ =====
246
+
247
+ Order = 0 corresponds to interpolation.
248
+ Only supply so many points you think makes sense
249
+ to around x0 when extracting the derivative (the function
250
+ need to be well behaved within that region). Also beware
251
+ of Runge's phenomenon.
252
+
253
+ See also
254
+ ========
255
+
256
+ sympy.calculus.finite_diff.finite_diff_weights
257
+
258
+ References
259
+ ==========
260
+
261
+ Fortran 90 implementation with Python interface for numerics: finitediff_
262
+
263
+ .. _finitediff: https://github.com/bjodah/finitediff
264
+
265
+ """
266
+
267
+ # In the original paper the following holds for the notation:
268
+ # M = order
269
+ # N = len(x_list) - 1
270
+
271
+ N = len(x_list) - 1
272
+ if len(x_list) != len(y_list):
273
+ raise ValueError("x_list and y_list not equal in length.")
274
+
275
+ delta = finite_diff_weights(order, x_list, x0)
276
+
277
+ derivative = 0
278
+ for nu in range(len(x_list)):
279
+ derivative += delta[order][N][nu]*y_list[nu]
280
+ return derivative
281
+
282
+
283
+ def _as_finite_diff(derivative, points=1, x0=None, wrt=None):
284
+ """
285
+ Returns an approximation of a derivative of a function in
286
+ the form of a finite difference formula. The expression is a
287
+ weighted sum of the function at a number of discrete values of
288
+ (one of) the independent variable(s).
289
+
290
+ Parameters
291
+ ==========
292
+
293
+ derivative: a Derivative instance
294
+
295
+ points: sequence or coefficient, optional
296
+ If sequence: discrete values (length >= order+1) of the
297
+ independent variable used for generating the finite
298
+ difference weights.
299
+ If it is a coefficient, it will be used as the step-size
300
+ for generating an equidistant sequence of length order+1
301
+ centered around ``x0``. default: 1 (step-size 1)
302
+
303
+ x0: number or Symbol, optional
304
+ the value of the independent variable (``wrt``) at which the
305
+ derivative is to be approximated. Default: same as ``wrt``.
306
+
307
+ wrt: Symbol, optional
308
+ "with respect to" the variable for which the (partial)
309
+ derivative is to be approximated for. If not provided it
310
+ is required that the Derivative is ordinary. Default: ``None``.
311
+
312
+ Examples
313
+ ========
314
+
315
+ >>> from sympy import symbols, Function, exp, sqrt, Symbol
316
+ >>> from sympy.calculus.finite_diff import _as_finite_diff
317
+ >>> x, h = symbols('x h')
318
+ >>> f = Function('f')
319
+ >>> _as_finite_diff(f(x).diff(x))
320
+ -f(x - 1/2) + f(x + 1/2)
321
+
322
+ The default step size and number of points are 1 and ``order + 1``
323
+ respectively. We can change the step size by passing a symbol
324
+ as a parameter:
325
+
326
+ >>> _as_finite_diff(f(x).diff(x), h)
327
+ -f(-h/2 + x)/h + f(h/2 + x)/h
328
+
329
+ We can also specify the discretized values to be used in a sequence:
330
+
331
+ >>> _as_finite_diff(f(x).diff(x), [x, x+h, x+2*h])
332
+ -3*f(x)/(2*h) + 2*f(h + x)/h - f(2*h + x)/(2*h)
333
+
334
+ The algorithm is not restricted to use equidistant spacing, nor
335
+ do we need to make the approximation around ``x0``, but we can get
336
+ an expression estimating the derivative at an offset:
337
+
338
+ >>> e, sq2 = exp(1), sqrt(2)
339
+ >>> xl = [x-h, x+h, x+e*h]
340
+ >>> _as_finite_diff(f(x).diff(x, 1), xl, x+h*sq2)
341
+ 2*h*((h + sqrt(2)*h)/(2*h) - (-sqrt(2)*h + h)/(2*h))*f(E*h + x)/((-h + E*h)*(h + E*h)) +
342
+ (-(-sqrt(2)*h + h)/(2*h) - (-sqrt(2)*h + E*h)/(2*h))*f(-h + x)/(h + E*h) +
343
+ (-(h + sqrt(2)*h)/(2*h) + (-sqrt(2)*h + E*h)/(2*h))*f(h + x)/(-h + E*h)
344
+
345
+ Partial derivatives are also supported:
346
+
347
+ >>> y = Symbol('y')
348
+ >>> d2fdxdy=f(x,y).diff(x,y)
349
+ >>> _as_finite_diff(d2fdxdy, wrt=x)
350
+ -Derivative(f(x - 1/2, y), y) + Derivative(f(x + 1/2, y), y)
351
+
352
+ See also
353
+ ========
354
+
355
+ sympy.calculus.finite_diff.apply_finite_diff
356
+ sympy.calculus.finite_diff.finite_diff_weights
357
+
358
+ """
359
+ if derivative.is_Derivative:
360
+ pass
361
+ elif derivative.is_Atom:
362
+ return derivative
363
+ else:
364
+ return derivative.fromiter(
365
+ [_as_finite_diff(ar, points, x0, wrt) for ar
366
+ in derivative.args], **derivative.assumptions0)
367
+
368
+ if wrt is None:
369
+ old = None
370
+ for v in derivative.variables:
371
+ if old is v:
372
+ continue
373
+ derivative = _as_finite_diff(derivative, points, x0, v)
374
+ old = v
375
+ return derivative
376
+
377
+ order = derivative.variables.count(wrt)
378
+
379
+ if x0 is None:
380
+ x0 = wrt
381
+
382
+ if not iterable(points):
383
+ if getattr(points, 'is_Function', False) and wrt in points.args:
384
+ points = points.subs(wrt, x0)
385
+ # points is simply the step-size, let's make it a
386
+ # equidistant sequence centered around x0
387
+ if order % 2 == 0:
388
+ # even order => odd number of points, grid point included
389
+ points = [x0 + points*i for i
390
+ in range(-order//2, order//2 + 1)]
391
+ else:
392
+ # odd order => even number of points, half-way wrt grid point
393
+ points = [x0 + points*S(i)/2 for i
394
+ in range(-order, order + 1, 2)]
395
+ others = [wrt, 0]
396
+ for v in set(derivative.variables):
397
+ if v == wrt:
398
+ continue
399
+ others += [v, derivative.variables.count(v)]
400
+ if len(points) < order+1:
401
+ raise ValueError("Too few points for order %d" % order)
402
+ return apply_finite_diff(order, points, [
403
+ Derivative(derivative.expr.subs({wrt: x}), *others) for
404
+ x in points], x0)
405
+
406
+
407
+ def differentiate_finite(expr, *symbols,
408
+ points=1, x0=None, wrt=None, evaluate=False):
409
+ r""" Differentiate expr and replace Derivatives with finite differences.
410
+
411
+ Parameters
412
+ ==========
413
+
414
+ expr : expression
415
+ \*symbols : differentiate with respect to symbols
416
+ points: sequence, coefficient or undefined function, optional
417
+ see ``Derivative.as_finite_difference``
418
+ x0: number or Symbol, optional
419
+ see ``Derivative.as_finite_difference``
420
+ wrt: Symbol, optional
421
+ see ``Derivative.as_finite_difference``
422
+
423
+ Examples
424
+ ========
425
+
426
+ >>> from sympy import sin, Function, differentiate_finite
427
+ >>> from sympy.abc import x, y, h
428
+ >>> f, g = Function('f'), Function('g')
429
+ >>> differentiate_finite(f(x)*g(x), x, points=[x-h, x+h])
430
+ -f(-h + x)*g(-h + x)/(2*h) + f(h + x)*g(h + x)/(2*h)
431
+
432
+ ``differentiate_finite`` works on any expression, including the expressions
433
+ with embedded derivatives:
434
+
435
+ >>> differentiate_finite(f(x) + sin(x), x, 2)
436
+ -2*f(x) + f(x - 1) + f(x + 1) - 2*sin(x) + sin(x - 1) + sin(x + 1)
437
+ >>> differentiate_finite(f(x, y), x, y)
438
+ f(x - 1/2, y - 1/2) - f(x - 1/2, y + 1/2) - f(x + 1/2, y - 1/2) + f(x + 1/2, y + 1/2)
439
+ >>> differentiate_finite(f(x)*g(x).diff(x), x)
440
+ (-g(x) + g(x + 1))*f(x + 1/2) - (g(x) - g(x - 1))*f(x - 1/2)
441
+
442
+ To make finite difference with non-constant discretization step use
443
+ undefined functions:
444
+
445
+ >>> dx = Function('dx')
446
+ >>> differentiate_finite(f(x)*g(x).diff(x), points=dx(x))
447
+ -(-g(x - dx(x)/2 - dx(x - dx(x)/2)/2)/dx(x - dx(x)/2) +
448
+ g(x - dx(x)/2 + dx(x - dx(x)/2)/2)/dx(x - dx(x)/2))*f(x - dx(x)/2)/dx(x) +
449
+ (-g(x + dx(x)/2 - dx(x + dx(x)/2)/2)/dx(x + dx(x)/2) +
450
+ g(x + dx(x)/2 + dx(x + dx(x)/2)/2)/dx(x + dx(x)/2))*f(x + dx(x)/2)/dx(x)
451
+
452
+ """
453
+ if any(term.is_Derivative for term in list(preorder_traversal(expr))):
454
+ evaluate = False
455
+
456
+ Dexpr = expr.diff(*symbols, evaluate=evaluate)
457
+ if evaluate:
458
+ sympy_deprecation_warning("""
459
+ The evaluate flag to differentiate_finite() is deprecated.
460
+
461
+ evaluate=True expands the intermediate derivatives before computing
462
+ differences, but this usually not what you want, as it does not
463
+ satisfy the product rule.
464
+ """,
465
+ deprecated_since_version="1.5",
466
+ active_deprecations_target="deprecated-differentiate_finite-evaluate",
467
+ )
468
+ return Dexpr.replace(
469
+ lambda arg: arg.is_Derivative,
470
+ lambda arg: arg.as_finite_difference(points=points, x0=x0, wrt=wrt))
471
+ else:
472
+ DFexpr = Dexpr.as_finite_difference(points=points, x0=x0, wrt=wrt)
473
+ return DFexpr.replace(
474
+ lambda arg: isinstance(arg, Subs),
475
+ lambda arg: arg.expr.as_finite_difference(
476
+ points=points, x0=arg.point[0], wrt=arg.variables[0]))
llmeval-env/lib/python3.10/site-packages/sympy/calculus/singularities.py ADDED
@@ -0,0 +1,398 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ Singularities
3
+ =============
4
+
5
+ This module implements algorithms for finding singularities for a function
6
+ and identifying types of functions.
7
+
8
+ The differential calculus methods in this module include methods to identify
9
+ the following function types in the given ``Interval``:
10
+ - Increasing
11
+ - Strictly Increasing
12
+ - Decreasing
13
+ - Strictly Decreasing
14
+ - Monotonic
15
+
16
+ """
17
+
18
+ from sympy.core.power import Pow
19
+ from sympy.core.singleton import S
20
+ from sympy.core.symbol import Symbol
21
+ from sympy.core.sympify import sympify
22
+ from sympy.functions.elementary.exponential import log
23
+ from sympy.functions.elementary.trigonometric import sec, csc, cot, tan, cos
24
+ from sympy.utilities.misc import filldedent
25
+
26
+
27
+ def singularities(expression, symbol, domain=None):
28
+ """
29
+ Find singularities of a given function.
30
+
31
+ Parameters
32
+ ==========
33
+
34
+ expression : Expr
35
+ The target function in which singularities need to be found.
36
+ symbol : Symbol
37
+ The symbol over the values of which the singularity in
38
+ expression in being searched for.
39
+
40
+ Returns
41
+ =======
42
+
43
+ Set
44
+ A set of values for ``symbol`` for which ``expression`` has a
45
+ singularity. An ``EmptySet`` is returned if ``expression`` has no
46
+ singularities for any given value of ``Symbol``.
47
+
48
+ Raises
49
+ ======
50
+
51
+ NotImplementedError
52
+ Methods for determining the singularities of this function have
53
+ not been developed.
54
+
55
+ Notes
56
+ =====
57
+
58
+ This function does not find non-isolated singularities
59
+ nor does it find branch points of the expression.
60
+
61
+ Currently supported functions are:
62
+ - univariate continuous (real or complex) functions
63
+
64
+ References
65
+ ==========
66
+
67
+ .. [1] https://en.wikipedia.org/wiki/Mathematical_singularity
68
+
69
+ Examples
70
+ ========
71
+
72
+ >>> from sympy import singularities, Symbol, log
73
+ >>> x = Symbol('x', real=True)
74
+ >>> y = Symbol('y', real=False)
75
+ >>> singularities(x**2 + x + 1, x)
76
+ EmptySet
77
+ >>> singularities(1/(x + 1), x)
78
+ {-1}
79
+ >>> singularities(1/(y**2 + 1), y)
80
+ {-I, I}
81
+ >>> singularities(1/(y**3 + 1), y)
82
+ {-1, 1/2 - sqrt(3)*I/2, 1/2 + sqrt(3)*I/2}
83
+ >>> singularities(log(x), x)
84
+ {0}
85
+
86
+ """
87
+ from sympy.solvers.solveset import solveset
88
+
89
+ if domain is None:
90
+ domain = S.Reals if symbol.is_real else S.Complexes
91
+ try:
92
+ sings = S.EmptySet
93
+ for i in expression.rewrite([sec, csc, cot, tan], cos).atoms(Pow):
94
+ if i.exp.is_infinite:
95
+ raise NotImplementedError
96
+ if i.exp.is_negative:
97
+ sings += solveset(i.base, symbol, domain)
98
+ for i in expression.atoms(log):
99
+ sings += solveset(i.args[0], symbol, domain)
100
+ return sings
101
+ except NotImplementedError:
102
+ raise NotImplementedError(filldedent('''
103
+ Methods for determining the singularities
104
+ of this function have not been developed.'''))
105
+
106
+
107
+ ###########################################################################
108
+ # DIFFERENTIAL CALCULUS METHODS #
109
+ ###########################################################################
110
+
111
+
112
+ def monotonicity_helper(expression, predicate, interval=S.Reals, symbol=None):
113
+ """
114
+ Helper function for functions checking function monotonicity.
115
+
116
+ Parameters
117
+ ==========
118
+
119
+ expression : Expr
120
+ The target function which is being checked
121
+ predicate : function
122
+ The property being tested for. The function takes in an integer
123
+ and returns a boolean. The integer input is the derivative and
124
+ the boolean result should be true if the property is being held,
125
+ and false otherwise.
126
+ interval : Set, optional
127
+ The range of values in which we are testing, defaults to all reals.
128
+ symbol : Symbol, optional
129
+ The symbol present in expression which gets varied over the given range.
130
+
131
+ It returns a boolean indicating whether the interval in which
132
+ the function's derivative satisfies given predicate is a superset
133
+ of the given interval.
134
+
135
+ Returns
136
+ =======
137
+
138
+ Boolean
139
+ True if ``predicate`` is true for all the derivatives when ``symbol``
140
+ is varied in ``range``, False otherwise.
141
+
142
+ """
143
+ from sympy.solvers.solveset import solveset
144
+
145
+ expression = sympify(expression)
146
+ free = expression.free_symbols
147
+
148
+ if symbol is None:
149
+ if len(free) > 1:
150
+ raise NotImplementedError(
151
+ 'The function has not yet been implemented'
152
+ ' for all multivariate expressions.'
153
+ )
154
+
155
+ variable = symbol or (free.pop() if free else Symbol('x'))
156
+ derivative = expression.diff(variable)
157
+ predicate_interval = solveset(predicate(derivative), variable, S.Reals)
158
+ return interval.is_subset(predicate_interval)
159
+
160
+
161
+ def is_increasing(expression, interval=S.Reals, symbol=None):
162
+ """
163
+ Return whether the function is increasing in the given interval.
164
+
165
+ Parameters
166
+ ==========
167
+
168
+ expression : Expr
169
+ The target function which is being checked.
170
+ interval : Set, optional
171
+ The range of values in which we are testing (defaults to set of
172
+ all real numbers).
173
+ symbol : Symbol, optional
174
+ The symbol present in expression which gets varied over the given range.
175
+
176
+ Returns
177
+ =======
178
+
179
+ Boolean
180
+ True if ``expression`` is increasing (either strictly increasing or
181
+ constant) in the given ``interval``, False otherwise.
182
+
183
+ Examples
184
+ ========
185
+
186
+ >>> from sympy import is_increasing
187
+ >>> from sympy.abc import x, y
188
+ >>> from sympy import S, Interval, oo
189
+ >>> is_increasing(x**3 - 3*x**2 + 4*x, S.Reals)
190
+ True
191
+ >>> is_increasing(-x**2, Interval(-oo, 0))
192
+ True
193
+ >>> is_increasing(-x**2, Interval(0, oo))
194
+ False
195
+ >>> is_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval(-2, 3))
196
+ False
197
+ >>> is_increasing(x**2 + y, Interval(1, 2), x)
198
+ True
199
+
200
+ """
201
+ return monotonicity_helper(expression, lambda x: x >= 0, interval, symbol)
202
+
203
+
204
+ def is_strictly_increasing(expression, interval=S.Reals, symbol=None):
205
+ """
206
+ Return whether the function is strictly increasing in the given interval.
207
+
208
+ Parameters
209
+ ==========
210
+
211
+ expression : Expr
212
+ The target function which is being checked.
213
+ interval : Set, optional
214
+ The range of values in which we are testing (defaults to set of
215
+ all real numbers).
216
+ symbol : Symbol, optional
217
+ The symbol present in expression which gets varied over the given range.
218
+
219
+ Returns
220
+ =======
221
+
222
+ Boolean
223
+ True if ``expression`` is strictly increasing in the given ``interval``,
224
+ False otherwise.
225
+
226
+ Examples
227
+ ========
228
+
229
+ >>> from sympy import is_strictly_increasing
230
+ >>> from sympy.abc import x, y
231
+ >>> from sympy import Interval, oo
232
+ >>> is_strictly_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval.Ropen(-oo, -2))
233
+ True
234
+ >>> is_strictly_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval.Lopen(3, oo))
235
+ True
236
+ >>> is_strictly_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval.open(-2, 3))
237
+ False
238
+ >>> is_strictly_increasing(-x**2, Interval(0, oo))
239
+ False
240
+ >>> is_strictly_increasing(-x**2 + y, Interval(-oo, 0), x)
241
+ False
242
+
243
+ """
244
+ return monotonicity_helper(expression, lambda x: x > 0, interval, symbol)
245
+
246
+
247
+ def is_decreasing(expression, interval=S.Reals, symbol=None):
248
+ """
249
+ Return whether the function is decreasing in the given interval.
250
+
251
+ Parameters
252
+ ==========
253
+
254
+ expression : Expr
255
+ The target function which is being checked.
256
+ interval : Set, optional
257
+ The range of values in which we are testing (defaults to set of
258
+ all real numbers).
259
+ symbol : Symbol, optional
260
+ The symbol present in expression which gets varied over the given range.
261
+
262
+ Returns
263
+ =======
264
+
265
+ Boolean
266
+ True if ``expression`` is decreasing (either strictly decreasing or
267
+ constant) in the given ``interval``, False otherwise.
268
+
269
+ Examples
270
+ ========
271
+
272
+ >>> from sympy import is_decreasing
273
+ >>> from sympy.abc import x, y
274
+ >>> from sympy import S, Interval, oo
275
+ >>> is_decreasing(1/(x**2 - 3*x), Interval.open(S(3)/2, 3))
276
+ True
277
+ >>> is_decreasing(1/(x**2 - 3*x), Interval.open(1.5, 3))
278
+ True
279
+ >>> is_decreasing(1/(x**2 - 3*x), Interval.Lopen(3, oo))
280
+ True
281
+ >>> is_decreasing(1/(x**2 - 3*x), Interval.Ropen(-oo, S(3)/2))
282
+ False
283
+ >>> is_decreasing(1/(x**2 - 3*x), Interval.Ropen(-oo, 1.5))
284
+ False
285
+ >>> is_decreasing(-x**2, Interval(-oo, 0))
286
+ False
287
+ >>> is_decreasing(-x**2 + y, Interval(-oo, 0), x)
288
+ False
289
+
290
+ """
291
+ return monotonicity_helper(expression, lambda x: x <= 0, interval, symbol)
292
+
293
+
294
+ def is_strictly_decreasing(expression, interval=S.Reals, symbol=None):
295
+ """
296
+ Return whether the function is strictly decreasing in the given interval.
297
+
298
+ Parameters
299
+ ==========
300
+
301
+ expression : Expr
302
+ The target function which is being checked.
303
+ interval : Set, optional
304
+ The range of values in which we are testing (defaults to set of
305
+ all real numbers).
306
+ symbol : Symbol, optional
307
+ The symbol present in expression which gets varied over the given range.
308
+
309
+ Returns
310
+ =======
311
+
312
+ Boolean
313
+ True if ``expression`` is strictly decreasing in the given ``interval``,
314
+ False otherwise.
315
+
316
+ Examples
317
+ ========
318
+
319
+ >>> from sympy import is_strictly_decreasing
320
+ >>> from sympy.abc import x, y
321
+ >>> from sympy import S, Interval, oo
322
+ >>> is_strictly_decreasing(1/(x**2 - 3*x), Interval.Lopen(3, oo))
323
+ True
324
+ >>> is_strictly_decreasing(1/(x**2 - 3*x), Interval.Ropen(-oo, S(3)/2))
325
+ False
326
+ >>> is_strictly_decreasing(1/(x**2 - 3*x), Interval.Ropen(-oo, 1.5))
327
+ False
328
+ >>> is_strictly_decreasing(-x**2, Interval(-oo, 0))
329
+ False
330
+ >>> is_strictly_decreasing(-x**2 + y, Interval(-oo, 0), x)
331
+ False
332
+
333
+ """
334
+ return monotonicity_helper(expression, lambda x: x < 0, interval, symbol)
335
+
336
+
337
+ def is_monotonic(expression, interval=S.Reals, symbol=None):
338
+ """
339
+ Return whether the function is monotonic in the given interval.
340
+
341
+ Parameters
342
+ ==========
343
+
344
+ expression : Expr
345
+ The target function which is being checked.
346
+ interval : Set, optional
347
+ The range of values in which we are testing (defaults to set of
348
+ all real numbers).
349
+ symbol : Symbol, optional
350
+ The symbol present in expression which gets varied over the given range.
351
+
352
+ Returns
353
+ =======
354
+
355
+ Boolean
356
+ True if ``expression`` is monotonic in the given ``interval``,
357
+ False otherwise.
358
+
359
+ Raises
360
+ ======
361
+
362
+ NotImplementedError
363
+ Monotonicity check has not been implemented for the queried function.
364
+
365
+ Examples
366
+ ========
367
+
368
+ >>> from sympy import is_monotonic
369
+ >>> from sympy.abc import x, y
370
+ >>> from sympy import S, Interval, oo
371
+ >>> is_monotonic(1/(x**2 - 3*x), Interval.open(S(3)/2, 3))
372
+ True
373
+ >>> is_monotonic(1/(x**2 - 3*x), Interval.open(1.5, 3))
374
+ True
375
+ >>> is_monotonic(1/(x**2 - 3*x), Interval.Lopen(3, oo))
376
+ True
377
+ >>> is_monotonic(x**3 - 3*x**2 + 4*x, S.Reals)
378
+ True
379
+ >>> is_monotonic(-x**2, S.Reals)
380
+ False
381
+ >>> is_monotonic(x**2 + y + 1, Interval(1, 2), x)
382
+ True
383
+
384
+ """
385
+ from sympy.solvers.solveset import solveset
386
+
387
+ expression = sympify(expression)
388
+
389
+ free = expression.free_symbols
390
+ if symbol is None and len(free) > 1:
391
+ raise NotImplementedError(
392
+ 'is_monotonic has not yet been implemented'
393
+ ' for all multivariate expressions.'
394
+ )
395
+
396
+ variable = symbol or (free.pop() if free else Symbol('x'))
397
+ turning_points = solveset(expression.diff(variable), variable, interval)
398
+ return interval.intersection(turning_points) is S.EmptySet
llmeval-env/lib/python3.10/site-packages/sympy/calculus/tests/test_accumulationbounds.py ADDED
@@ -0,0 +1,336 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.numbers import (E, Rational, oo, pi, zoo)
2
+ from sympy.core.singleton import S
3
+ from sympy.core.symbol import Symbol
4
+ from sympy.functions.elementary.exponential import (exp, log)
5
+ from sympy.functions.elementary.miscellaneous import (Max, Min, sqrt)
6
+ from sympy.functions.elementary.trigonometric import (cos, sin, tan)
7
+ from sympy.calculus.accumulationbounds import AccumBounds
8
+ from sympy.core import Add, Mul, Pow
9
+ from sympy.core.expr import unchanged
10
+ from sympy.testing.pytest import raises, XFAIL
11
+ from sympy.abc import x
12
+
13
+ a = Symbol('a', real=True)
14
+ B = AccumBounds
15
+
16
+
17
+ def test_AccumBounds():
18
+ assert B(1, 2).args == (1, 2)
19
+ assert B(1, 2).delta is S.One
20
+ assert B(1, 2).mid == Rational(3, 2)
21
+ assert B(1, 3).is_real == True
22
+
23
+ assert B(1, 1) is S.One
24
+
25
+ assert B(1, 2) + 1 == B(2, 3)
26
+ assert 1 + B(1, 2) == B(2, 3)
27
+ assert B(1, 2) + B(2, 3) == B(3, 5)
28
+
29
+ assert -B(1, 2) == B(-2, -1)
30
+
31
+ assert B(1, 2) - 1 == B(0, 1)
32
+ assert 1 - B(1, 2) == B(-1, 0)
33
+ assert B(2, 3) - B(1, 2) == B(0, 2)
34
+
35
+ assert x + B(1, 2) == Add(B(1, 2), x)
36
+ assert a + B(1, 2) == B(1 + a, 2 + a)
37
+ assert B(1, 2) - x == Add(B(1, 2), -x)
38
+
39
+ assert B(-oo, 1) + oo == B(-oo, oo)
40
+ assert B(1, oo) + oo is oo
41
+ assert B(1, oo) - oo == B(-oo, oo)
42
+ assert (-oo - B(-1, oo)) is -oo
43
+ assert B(-oo, 1) - oo is -oo
44
+
45
+ assert B(1, oo) - oo == B(-oo, oo)
46
+ assert B(-oo, 1) - (-oo) == B(-oo, oo)
47
+ assert (oo - B(1, oo)) == B(-oo, oo)
48
+ assert (-oo - B(1, oo)) is -oo
49
+
50
+ assert B(1, 2)/2 == B(S.Half, 1)
51
+ assert 2/B(2, 3) == B(Rational(2, 3), 1)
52
+ assert 1/B(-1, 1) == B(-oo, oo)
53
+
54
+ assert abs(B(1, 2)) == B(1, 2)
55
+ assert abs(B(-2, -1)) == B(1, 2)
56
+ assert abs(B(-2, 1)) == B(0, 2)
57
+ assert abs(B(-1, 2)) == B(0, 2)
58
+ c = Symbol('c')
59
+ raises(ValueError, lambda: B(0, c))
60
+ raises(ValueError, lambda: B(1, -1))
61
+ r = Symbol('r', real=True)
62
+ raises(ValueError, lambda: B(r, r - 1))
63
+
64
+
65
+ def test_AccumBounds_mul():
66
+ assert B(1, 2)*2 == B(2, 4)
67
+ assert 2*B(1, 2) == B(2, 4)
68
+ assert B(1, 2)*B(2, 3) == B(2, 6)
69
+ assert B(0, 2)*B(2, oo) == B(0, oo)
70
+ l, r = B(-oo, oo), B(-a, a)
71
+ assert l*r == B(-oo, oo)
72
+ assert r*l == B(-oo, oo)
73
+ l, r = B(1, oo), B(-3, -2)
74
+ assert l*r == B(-oo, -2)
75
+ assert r*l == B(-oo, -2)
76
+ assert B(1, 2)*0 == 0
77
+ assert B(1, oo)*0 == B(0, oo)
78
+ assert B(-oo, 1)*0 == B(-oo, 0)
79
+ assert B(-oo, oo)*0 == B(-oo, oo)
80
+
81
+ assert B(1, 2)*x == Mul(B(1, 2), x, evaluate=False)
82
+
83
+ assert B(0, 2)*oo == B(0, oo)
84
+ assert B(-2, 0)*oo == B(-oo, 0)
85
+ assert B(0, 2)*(-oo) == B(-oo, 0)
86
+ assert B(-2, 0)*(-oo) == B(0, oo)
87
+ assert B(-1, 1)*oo == B(-oo, oo)
88
+ assert B(-1, 1)*(-oo) == B(-oo, oo)
89
+ assert B(-oo, oo)*oo == B(-oo, oo)
90
+
91
+
92
+ def test_AccumBounds_div():
93
+ assert B(-1, 3)/B(3, 4) == B(Rational(-1, 3), 1)
94
+ assert B(-2, 4)/B(-3, 4) == B(-oo, oo)
95
+ assert B(-3, -2)/B(-4, 0) == B(S.Half, oo)
96
+
97
+ # these two tests can have a better answer
98
+ # after Union of B is improved
99
+ assert B(-3, -2)/B(-2, 1) == B(-oo, oo)
100
+ assert B(2, 3)/B(-2, 2) == B(-oo, oo)
101
+
102
+ assert B(-3, -2)/B(0, 4) == B(-oo, Rational(-1, 2))
103
+ assert B(2, 4)/B(-3, 0) == B(-oo, Rational(-2, 3))
104
+ assert B(2, 4)/B(0, 3) == B(Rational(2, 3), oo)
105
+
106
+ assert B(0, 1)/B(0, 1) == B(0, oo)
107
+ assert B(-1, 0)/B(0, 1) == B(-oo, 0)
108
+ assert B(-1, 2)/B(-2, 2) == B(-oo, oo)
109
+
110
+ assert 1/B(-1, 2) == B(-oo, oo)
111
+ assert 1/B(0, 2) == B(S.Half, oo)
112
+ assert (-1)/B(0, 2) == B(-oo, Rational(-1, 2))
113
+ assert 1/B(-oo, 0) == B(-oo, 0)
114
+ assert 1/B(-1, 0) == B(-oo, -1)
115
+ assert (-2)/B(-oo, 0) == B(0, oo)
116
+ assert 1/B(-oo, -1) == B(-1, 0)
117
+
118
+ assert B(1, 2)/a == Mul(B(1, 2), 1/a, evaluate=False)
119
+
120
+ assert B(1, 2)/0 == B(1, 2)*zoo
121
+ assert B(1, oo)/oo == B(0, oo)
122
+ assert B(1, oo)/(-oo) == B(-oo, 0)
123
+ assert B(-oo, -1)/oo == B(-oo, 0)
124
+ assert B(-oo, -1)/(-oo) == B(0, oo)
125
+ assert B(-oo, oo)/oo == B(-oo, oo)
126
+ assert B(-oo, oo)/(-oo) == B(-oo, oo)
127
+ assert B(-1, oo)/oo == B(0, oo)
128
+ assert B(-1, oo)/(-oo) == B(-oo, 0)
129
+ assert B(-oo, 1)/oo == B(-oo, 0)
130
+ assert B(-oo, 1)/(-oo) == B(0, oo)
131
+
132
+
133
+ def test_issue_18795():
134
+ r = Symbol('r', real=True)
135
+ a = B(-1,1)
136
+ c = B(7, oo)
137
+ b = B(-oo, oo)
138
+ assert c - tan(r) == B(7-tan(r), oo)
139
+ assert b + tan(r) == B(-oo, oo)
140
+ assert (a + r)/a == B(-oo, oo)*B(r - 1, r + 1)
141
+ assert (b + a)/a == B(-oo, oo)
142
+
143
+
144
+ def test_AccumBounds_func():
145
+ assert (x**2 + 2*x + 1).subs(x, B(-1, 1)) == B(-1, 4)
146
+ assert exp(B(0, 1)) == B(1, E)
147
+ assert exp(B(-oo, oo)) == B(0, oo)
148
+ assert log(B(3, 6)) == B(log(3), log(6))
149
+
150
+
151
+ @XFAIL
152
+ def test_AccumBounds_powf():
153
+ nn = Symbol('nn', nonnegative=True)
154
+ assert B(1 + nn, 2 + nn)**B(1, 2) == B(1 + nn, (2 + nn)**2)
155
+ i = Symbol('i', integer=True, negative=True)
156
+ assert B(1, 2)**i == B(2**i, 1)
157
+
158
+
159
+ def test_AccumBounds_pow():
160
+ assert B(0, 2)**2 == B(0, 4)
161
+ assert B(-1, 1)**2 == B(0, 1)
162
+ assert B(1, 2)**2 == B(1, 4)
163
+ assert B(-1, 2)**3 == B(-1, 8)
164
+ assert B(-1, 1)**0 == 1
165
+
166
+ assert B(1, 2)**Rational(5, 2) == B(1, 4*sqrt(2))
167
+ assert B(0, 2)**S.Half == B(0, sqrt(2))
168
+
169
+ neg = Symbol('neg', negative=True)
170
+ assert unchanged(Pow, B(neg, 1), S.Half)
171
+ nn = Symbol('nn', nonnegative=True)
172
+ assert B(nn, nn + 1)**S.Half == B(sqrt(nn), sqrt(nn + 1))
173
+ assert B(nn, nn + 1)**nn == B(nn**nn, (nn + 1)**nn)
174
+ assert unchanged(Pow, B(nn, nn + 1), x)
175
+ i = Symbol('i', integer=True)
176
+ assert B(1, 2)**i == B(Min(1, 2**i), Max(1, 2**i))
177
+ i = Symbol('i', integer=True, nonnegative=True)
178
+ assert B(1, 2)**i == B(1, 2**i)
179
+ assert B(0, 1)**i == B(0**i, 1)
180
+
181
+ assert B(1, 5)**(-2) == B(Rational(1, 25), 1)
182
+ assert B(-1, 3)**(-2) == B(0, oo)
183
+ assert B(0, 2)**(-3) == B(Rational(1, 8), oo)
184
+ assert B(-2, 0)**(-3) == B(-oo, -Rational(1, 8))
185
+ assert B(0, 2)**(-2) == B(Rational(1, 4), oo)
186
+ assert B(-1, 2)**(-3) == B(-oo, oo)
187
+ assert B(-3, -2)**(-3) == B(Rational(-1, 8), Rational(-1, 27))
188
+ assert B(-3, -2)**(-2) == B(Rational(1, 9), Rational(1, 4))
189
+ assert B(0, oo)**S.Half == B(0, oo)
190
+ assert B(-oo, 0)**(-2) == B(0, oo)
191
+ assert B(-2, 0)**(-2) == B(Rational(1, 4), oo)
192
+
193
+ assert B(Rational(1, 3), S.Half)**oo is S.Zero
194
+ assert B(0, S.Half)**oo is S.Zero
195
+ assert B(S.Half, 1)**oo == B(0, oo)
196
+ assert B(0, 1)**oo == B(0, oo)
197
+ assert B(2, 3)**oo is oo
198
+ assert B(1, 2)**oo == B(0, oo)
199
+ assert B(S.Half, 3)**oo == B(0, oo)
200
+ assert B(Rational(-1, 3), Rational(-1, 4))**oo is S.Zero
201
+ assert B(-1, Rational(-1, 2))**oo is S.NaN
202
+ assert B(-3, -2)**oo is zoo
203
+ assert B(-2, -1)**oo is S.NaN
204
+ assert B(-2, Rational(-1, 2))**oo is S.NaN
205
+ assert B(Rational(-1, 2), S.Half)**oo is S.Zero
206
+ assert B(Rational(-1, 2), 1)**oo == B(0, oo)
207
+ assert B(Rational(-2, 3), 2)**oo == B(0, oo)
208
+ assert B(-1, 1)**oo == B(-oo, oo)
209
+ assert B(-1, S.Half)**oo == B(-oo, oo)
210
+ assert B(-1, 2)**oo == B(-oo, oo)
211
+ assert B(-2, S.Half)**oo == B(-oo, oo)
212
+
213
+ assert B(1, 2)**x == Pow(B(1, 2), x, evaluate=False)
214
+
215
+ assert B(2, 3)**(-oo) is S.Zero
216
+ assert B(0, 2)**(-oo) == B(0, oo)
217
+ assert B(-1, 2)**(-oo) == B(-oo, oo)
218
+
219
+ assert (tan(x)**sin(2*x)).subs(x, B(0, pi/2)) == \
220
+ Pow(B(-oo, oo), B(0, 1))
221
+
222
+
223
+ def test_AccumBounds_exponent():
224
+ # base is 0
225
+ z = 0**B(a, a + S.Half)
226
+ assert z.subs(a, 0) == B(0, 1)
227
+ assert z.subs(a, 1) == 0
228
+ p = z.subs(a, -1)
229
+ assert p.is_Pow and p.args == (0, B(-1, -S.Half))
230
+ # base > 0
231
+ # when base is 1 the type of bounds does not matter
232
+ assert 1**B(a, a + 1) == 1
233
+ # otherwise we need to know if 0 is in the bounds
234
+ assert S.Half**B(-2, 2) == B(S(1)/4, 4)
235
+ assert 2**B(-2, 2) == B(S(1)/4, 4)
236
+
237
+ # +eps may introduce +oo
238
+ # if there is a negative integer exponent
239
+ assert B(0, 1)**B(S(1)/2, 1) == B(0, 1)
240
+ assert B(0, 1)**B(0, 1) == B(0, 1)
241
+
242
+ # positive bases have positive bounds
243
+ assert B(2, 3)**B(-3, -2) == B(S(1)/27, S(1)/4)
244
+ assert B(2, 3)**B(-3, 2) == B(S(1)/27, 9)
245
+
246
+ # bounds generating imaginary parts unevaluated
247
+ assert unchanged(Pow, B(-1, 1), B(1, 2))
248
+ assert B(0, S(1)/2)**B(1, oo) == B(0, S(1)/2)
249
+ assert B(0, 1)**B(1, oo) == B(0, oo)
250
+ assert B(0, 2)**B(1, oo) == B(0, oo)
251
+ assert B(0, oo)**B(1, oo) == B(0, oo)
252
+ assert B(S(1)/2, 1)**B(1, oo) == B(0, oo)
253
+ assert B(S(1)/2, 1)**B(-oo, -1) == B(0, oo)
254
+ assert B(S(1)/2, 1)**B(-oo, oo) == B(0, oo)
255
+ assert B(S(1)/2, 2)**B(1, oo) == B(0, oo)
256
+ assert B(S(1)/2, 2)**B(-oo, -1) == B(0, oo)
257
+ assert B(S(1)/2, 2)**B(-oo, oo) == B(0, oo)
258
+ assert B(S(1)/2, oo)**B(1, oo) == B(0, oo)
259
+ assert B(S(1)/2, oo)**B(-oo, -1) == B(0, oo)
260
+ assert B(S(1)/2, oo)**B(-oo, oo) == B(0, oo)
261
+ assert B(1, 2)**B(1, oo) == B(0, oo)
262
+ assert B(1, 2)**B(-oo, -1) == B(0, oo)
263
+ assert B(1, 2)**B(-oo, oo) == B(0, oo)
264
+ assert B(1, oo)**B(1, oo) == B(0, oo)
265
+ assert B(1, oo)**B(-oo, -1) == B(0, oo)
266
+ assert B(1, oo)**B(-oo, oo) == B(0, oo)
267
+ assert B(2, oo)**B(1, oo) == B(2, oo)
268
+ assert B(2, oo)**B(-oo, -1) == B(0, S(1)/2)
269
+ assert B(2, oo)**B(-oo, oo) == B(0, oo)
270
+
271
+
272
+ def test_comparison_AccumBounds():
273
+ assert (B(1, 3) < 4) == S.true
274
+ assert (B(1, 3) < -1) == S.false
275
+ assert (B(1, 3) < 2).rel_op == '<'
276
+ assert (B(1, 3) <= 2).rel_op == '<='
277
+
278
+ assert (B(1, 3) > 4) == S.false
279
+ assert (B(1, 3) > -1) == S.true
280
+ assert (B(1, 3) > 2).rel_op == '>'
281
+ assert (B(1, 3) >= 2).rel_op == '>='
282
+
283
+ assert (B(1, 3) < B(4, 6)) == S.true
284
+ assert (B(1, 3) < B(2, 4)).rel_op == '<'
285
+ assert (B(1, 3) < B(-2, 0)) == S.false
286
+
287
+ assert (B(1, 3) <= B(4, 6)) == S.true
288
+ assert (B(1, 3) <= B(-2, 0)) == S.false
289
+
290
+ assert (B(1, 3) > B(4, 6)) == S.false
291
+ assert (B(1, 3) > B(-2, 0)) == S.true
292
+
293
+ assert (B(1, 3) >= B(4, 6)) == S.false
294
+ assert (B(1, 3) >= B(-2, 0)) == S.true
295
+
296
+ # issue 13499
297
+ assert (cos(x) > 0).subs(x, oo) == (B(-1, 1) > 0)
298
+
299
+ c = Symbol('c')
300
+ raises(TypeError, lambda: (B(0, 1) < c))
301
+ raises(TypeError, lambda: (B(0, 1) <= c))
302
+ raises(TypeError, lambda: (B(0, 1) > c))
303
+ raises(TypeError, lambda: (B(0, 1) >= c))
304
+
305
+
306
+ def test_contains_AccumBounds():
307
+ assert (1 in B(1, 2)) == S.true
308
+ raises(TypeError, lambda: a in B(1, 2))
309
+ assert 0 in B(-1, 0)
310
+ raises(TypeError, lambda:
311
+ (cos(1)**2 + sin(1)**2 - 1) in B(-1, 0))
312
+ assert (-oo in B(1, oo)) == S.true
313
+ assert (oo in B(-oo, 0)) == S.true
314
+
315
+ # issue 13159
316
+ assert Mul(0, B(-1, 1)) == Mul(B(-1, 1), 0) == 0
317
+ import itertools
318
+ for perm in itertools.permutations([0, B(-1, 1), x]):
319
+ assert Mul(*perm) == 0
320
+
321
+
322
+ def test_intersection_AccumBounds():
323
+ assert B(0, 3).intersection(B(1, 2)) == B(1, 2)
324
+ assert B(0, 3).intersection(B(1, 4)) == B(1, 3)
325
+ assert B(0, 3).intersection(B(-1, 2)) == B(0, 2)
326
+ assert B(0, 3).intersection(B(-1, 4)) == B(0, 3)
327
+ assert B(0, 1).intersection(B(2, 3)) == S.EmptySet
328
+ raises(TypeError, lambda: B(0, 3).intersection(1))
329
+
330
+
331
+ def test_union_AccumBounds():
332
+ assert B(0, 3).union(B(1, 2)) == B(0, 3)
333
+ assert B(0, 3).union(B(1, 4)) == B(0, 4)
334
+ assert B(0, 3).union(B(-1, 2)) == B(-1, 3)
335
+ assert B(0, 3).union(B(-1, 4)) == B(-1, 4)
336
+ raises(TypeError, lambda: B(0, 3).union(1))
llmeval-env/lib/python3.10/site-packages/sympy/calculus/tests/test_euler.py ADDED
@@ -0,0 +1,74 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.function import (Derivative as D, Function)
2
+ from sympy.core.relational import Eq
3
+ from sympy.core.symbol import (Symbol, symbols)
4
+ from sympy.functions.elementary.trigonometric import (cos, sin)
5
+ from sympy.testing.pytest import raises
6
+ from sympy.calculus.euler import euler_equations as euler
7
+
8
+
9
+ def test_euler_interface():
10
+ x = Function('x')
11
+ y = Symbol('y')
12
+ t = Symbol('t')
13
+ raises(TypeError, lambda: euler())
14
+ raises(TypeError, lambda: euler(D(x(t), t)*y(t), [x(t), y]))
15
+ raises(ValueError, lambda: euler(D(x(t), t)*x(y), [x(t), x(y)]))
16
+ raises(TypeError, lambda: euler(D(x(t), t)**2, x(0)))
17
+ raises(TypeError, lambda: euler(D(x(t), t)*y(t), [t]))
18
+ assert euler(D(x(t), t)**2/2, {x(t)}) == [Eq(-D(x(t), t, t), 0)]
19
+ assert euler(D(x(t), t)**2/2, x(t), {t}) == [Eq(-D(x(t), t, t), 0)]
20
+
21
+
22
+ def test_euler_pendulum():
23
+ x = Function('x')
24
+ t = Symbol('t')
25
+ L = D(x(t), t)**2/2 + cos(x(t))
26
+ assert euler(L, x(t), t) == [Eq(-sin(x(t)) - D(x(t), t, t), 0)]
27
+
28
+
29
+ def test_euler_henonheiles():
30
+ x = Function('x')
31
+ y = Function('y')
32
+ t = Symbol('t')
33
+ L = sum(D(z(t), t)**2/2 - z(t)**2/2 for z in [x, y])
34
+ L += -x(t)**2*y(t) + y(t)**3/3
35
+ assert euler(L, [x(t), y(t)], t) == [Eq(-2*x(t)*y(t) - x(t) -
36
+ D(x(t), t, t), 0),
37
+ Eq(-x(t)**2 + y(t)**2 -
38
+ y(t) - D(y(t), t, t), 0)]
39
+
40
+
41
+ def test_euler_sineg():
42
+ psi = Function('psi')
43
+ t = Symbol('t')
44
+ x = Symbol('x')
45
+ L = D(psi(t, x), t)**2/2 - D(psi(t, x), x)**2/2 + cos(psi(t, x))
46
+ assert euler(L, psi(t, x), [t, x]) == [Eq(-sin(psi(t, x)) -
47
+ D(psi(t, x), t, t) +
48
+ D(psi(t, x), x, x), 0)]
49
+
50
+
51
+ def test_euler_high_order():
52
+ # an example from hep-th/0309038
53
+ m = Symbol('m')
54
+ k = Symbol('k')
55
+ x = Function('x')
56
+ y = Function('y')
57
+ t = Symbol('t')
58
+ L = (m*D(x(t), t)**2/2 + m*D(y(t), t)**2/2 -
59
+ k*D(x(t), t)*D(y(t), t, t) + k*D(y(t), t)*D(x(t), t, t))
60
+ assert euler(L, [x(t), y(t)]) == [Eq(2*k*D(y(t), t, t, t) -
61
+ m*D(x(t), t, t), 0),
62
+ Eq(-2*k*D(x(t), t, t, t) -
63
+ m*D(y(t), t, t), 0)]
64
+
65
+ w = Symbol('w')
66
+ L = D(x(t, w), t, w)**2/2
67
+ assert euler(L) == [Eq(D(x(t, w), t, t, w, w), 0)]
68
+
69
+ def test_issue_18653():
70
+ x, y, z = symbols("x y z")
71
+ f, g, h = symbols("f g h", cls=Function, args=(x, y))
72
+ f, g, h = f(), g(), h()
73
+ expr2 = f.diff(x)*h.diff(z)
74
+ assert euler(expr2, (f,), (x, y)) == []
llmeval-env/lib/python3.10/site-packages/sympy/calculus/tests/test_singularities.py ADDED
@@ -0,0 +1,103 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.numbers import (I, Rational, oo)
2
+ from sympy.core.singleton import S
3
+ from sympy.core.symbol import Symbol
4
+ from sympy.functions.elementary.exponential import (exp, log)
5
+ from sympy.functions.elementary.miscellaneous import sqrt
6
+ from sympy.calculus.singularities import (
7
+ singularities,
8
+ is_increasing,
9
+ is_strictly_increasing,
10
+ is_decreasing,
11
+ is_strictly_decreasing,
12
+ is_monotonic
13
+ )
14
+ from sympy.sets import Interval, FiniteSet
15
+ from sympy.testing.pytest import raises
16
+ from sympy.abc import x, y
17
+
18
+
19
+ def test_singularities():
20
+ x = Symbol('x')
21
+ assert singularities(x**2, x) == S.EmptySet
22
+ assert singularities(x/(x**2 + 3*x + 2), x) == FiniteSet(-2, -1)
23
+ assert singularities(1/(x**2 + 1), x) == FiniteSet(I, -I)
24
+ assert singularities(x/(x**3 + 1), x) == \
25
+ FiniteSet(-1, (1 - sqrt(3) * I) / 2, (1 + sqrt(3) * I) / 2)
26
+ assert singularities(1/(y**2 + 2*I*y + 1), y) == \
27
+ FiniteSet(-I + sqrt(2)*I, -I - sqrt(2)*I)
28
+
29
+ x = Symbol('x', real=True)
30
+ assert singularities(1/(x**2 + 1), x) == S.EmptySet
31
+ assert singularities(exp(1/x), x, S.Reals) == FiniteSet(0)
32
+ assert singularities(exp(1/x), x, Interval(1, 2)) == S.EmptySet
33
+ assert singularities(log((x - 2)**2), x, Interval(1, 3)) == FiniteSet(2)
34
+ raises(NotImplementedError, lambda: singularities(x**-oo, x))
35
+
36
+
37
+ def test_is_increasing():
38
+ """Test whether is_increasing returns correct value."""
39
+ a = Symbol('a', negative=True)
40
+
41
+ assert is_increasing(x**3 - 3*x**2 + 4*x, S.Reals)
42
+ assert is_increasing(-x**2, Interval(-oo, 0))
43
+ assert not is_increasing(-x**2, Interval(0, oo))
44
+ assert not is_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval(-2, 3))
45
+ assert is_increasing(x**2 + y, Interval(1, oo), x)
46
+ assert is_increasing(-x**2*a, Interval(1, oo), x)
47
+ assert is_increasing(1)
48
+
49
+ assert is_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval(-2, 3)) is False
50
+
51
+
52
+ def test_is_strictly_increasing():
53
+ """Test whether is_strictly_increasing returns correct value."""
54
+ assert is_strictly_increasing(
55
+ 4*x**3 - 6*x**2 - 72*x + 30, Interval.Ropen(-oo, -2))
56
+ assert is_strictly_increasing(
57
+ 4*x**3 - 6*x**2 - 72*x + 30, Interval.Lopen(3, oo))
58
+ assert not is_strictly_increasing(
59
+ 4*x**3 - 6*x**2 - 72*x + 30, Interval.open(-2, 3))
60
+ assert not is_strictly_increasing(-x**2, Interval(0, oo))
61
+ assert not is_strictly_decreasing(1)
62
+
63
+ assert is_strictly_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval.open(-2, 3)) is False
64
+
65
+
66
+ def test_is_decreasing():
67
+ """Test whether is_decreasing returns correct value."""
68
+ b = Symbol('b', positive=True)
69
+
70
+ assert is_decreasing(1/(x**2 - 3*x), Interval.open(Rational(3,2), 3))
71
+ assert is_decreasing(1/(x**2 - 3*x), Interval.open(1.5, 3))
72
+ assert is_decreasing(1/(x**2 - 3*x), Interval.Lopen(3, oo))
73
+ assert not is_decreasing(1/(x**2 - 3*x), Interval.Ropen(-oo, Rational(3, 2)))
74
+ assert not is_decreasing(-x**2, Interval(-oo, 0))
75
+ assert not is_decreasing(-x**2*b, Interval(-oo, 0), x)
76
+
77
+
78
+ def test_is_strictly_decreasing():
79
+ """Test whether is_strictly_decreasing returns correct value."""
80
+ assert is_strictly_decreasing(1/(x**2 - 3*x), Interval.Lopen(3, oo))
81
+ assert not is_strictly_decreasing(
82
+ 1/(x**2 - 3*x), Interval.Ropen(-oo, Rational(3, 2)))
83
+ assert not is_strictly_decreasing(-x**2, Interval(-oo, 0))
84
+ assert not is_strictly_decreasing(1)
85
+ assert is_strictly_decreasing(1/(x**2 - 3*x), Interval.open(Rational(3,2), 3))
86
+ assert is_strictly_decreasing(1/(x**2 - 3*x), Interval.open(1.5, 3))
87
+
88
+
89
+ def test_is_monotonic():
90
+ """Test whether is_monotonic returns correct value."""
91
+ assert is_monotonic(1/(x**2 - 3*x), Interval.open(Rational(3,2), 3))
92
+ assert is_monotonic(1/(x**2 - 3*x), Interval.open(1.5, 3))
93
+ assert is_monotonic(1/(x**2 - 3*x), Interval.Lopen(3, oo))
94
+ assert is_monotonic(x**3 - 3*x**2 + 4*x, S.Reals)
95
+ assert not is_monotonic(-x**2, S.Reals)
96
+ assert is_monotonic(x**2 + y + 1, Interval(1, 2), x)
97
+ raises(NotImplementedError, lambda: is_monotonic(x**2 + y + 1))
98
+
99
+
100
+ def test_issue_23401():
101
+ x = Symbol('x')
102
+ expr = (x + 1)/(-1.0e-3*x**2 + 0.1*x + 0.1)
103
+ assert is_increasing(expr, Interval(1,2), x)
llmeval-env/lib/python3.10/site-packages/sympy/calculus/util.py ADDED
@@ -0,0 +1,841 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from .accumulationbounds import AccumBounds, AccumulationBounds # noqa: F401
2
+ from .singularities import singularities
3
+ from sympy.core import Pow, S
4
+ from sympy.core.function import diff, expand_mul
5
+ from sympy.core.kind import NumberKind
6
+ from sympy.core.mod import Mod
7
+ from sympy.core.numbers import equal_valued
8
+ from sympy.core.relational import Relational
9
+ from sympy.core.symbol import Symbol, Dummy
10
+ from sympy.core.sympify import _sympify
11
+ from sympy.functions.elementary.complexes import Abs, im, re
12
+ from sympy.functions.elementary.exponential import exp, log
13
+ from sympy.functions.elementary.piecewise import Piecewise
14
+ from sympy.functions.elementary.trigonometric import (
15
+ TrigonometricFunction, sin, cos, csc, sec)
16
+ from sympy.polys.polytools import degree, lcm_list
17
+ from sympy.sets.sets import (Interval, Intersection, FiniteSet, Union,
18
+ Complement)
19
+ from sympy.sets.fancysets import ImageSet
20
+ from sympy.utilities import filldedent
21
+ from sympy.utilities.iterables import iterable
22
+
23
+
24
+ def continuous_domain(f, symbol, domain):
25
+ """
26
+ Returns the intervals in the given domain for which the function
27
+ is continuous.
28
+ This method is limited by the ability to determine the various
29
+ singularities and discontinuities of the given function.
30
+
31
+ Parameters
32
+ ==========
33
+
34
+ f : :py:class:`~.Expr`
35
+ The concerned function.
36
+ symbol : :py:class:`~.Symbol`
37
+ The variable for which the intervals are to be determined.
38
+ domain : :py:class:`~.Interval`
39
+ The domain over which the continuity of the symbol has to be checked.
40
+
41
+ Examples
42
+ ========
43
+
44
+ >>> from sympy import Interval, Symbol, S, tan, log, pi, sqrt
45
+ >>> from sympy.calculus.util import continuous_domain
46
+ >>> x = Symbol('x')
47
+ >>> continuous_domain(1/x, x, S.Reals)
48
+ Union(Interval.open(-oo, 0), Interval.open(0, oo))
49
+ >>> continuous_domain(tan(x), x, Interval(0, pi))
50
+ Union(Interval.Ropen(0, pi/2), Interval.Lopen(pi/2, pi))
51
+ >>> continuous_domain(sqrt(x - 2), x, Interval(-5, 5))
52
+ Interval(2, 5)
53
+ >>> continuous_domain(log(2*x - 1), x, S.Reals)
54
+ Interval.open(1/2, oo)
55
+
56
+ Returns
57
+ =======
58
+
59
+ :py:class:`~.Interval`
60
+ Union of all intervals where the function is continuous.
61
+
62
+ Raises
63
+ ======
64
+
65
+ NotImplementedError
66
+ If the method to determine continuity of such a function
67
+ has not yet been developed.
68
+
69
+ """
70
+ from sympy.solvers.inequalities import solve_univariate_inequality
71
+
72
+ if domain.is_subset(S.Reals):
73
+ constrained_interval = domain
74
+ for atom in f.atoms(Pow):
75
+ den = atom.exp.as_numer_denom()[1]
76
+ if den.is_even and den.is_nonzero:
77
+ constraint = solve_univariate_inequality(atom.base >= 0,
78
+ symbol).as_set()
79
+ constrained_interval = Intersection(constraint,
80
+ constrained_interval)
81
+
82
+ for atom in f.atoms(log):
83
+ constraint = solve_univariate_inequality(atom.args[0] > 0,
84
+ symbol).as_set()
85
+ constrained_interval = Intersection(constraint,
86
+ constrained_interval)
87
+
88
+
89
+ return constrained_interval - singularities(f, symbol, domain)
90
+
91
+
92
+ def function_range(f, symbol, domain):
93
+ """
94
+ Finds the range of a function in a given domain.
95
+ This method is limited by the ability to determine the singularities and
96
+ determine limits.
97
+
98
+ Parameters
99
+ ==========
100
+
101
+ f : :py:class:`~.Expr`
102
+ The concerned function.
103
+ symbol : :py:class:`~.Symbol`
104
+ The variable for which the range of function is to be determined.
105
+ domain : :py:class:`~.Interval`
106
+ The domain under which the range of the function has to be found.
107
+
108
+ Examples
109
+ ========
110
+
111
+ >>> from sympy import Interval, Symbol, S, exp, log, pi, sqrt, sin, tan
112
+ >>> from sympy.calculus.util import function_range
113
+ >>> x = Symbol('x')
114
+ >>> function_range(sin(x), x, Interval(0, 2*pi))
115
+ Interval(-1, 1)
116
+ >>> function_range(tan(x), x, Interval(-pi/2, pi/2))
117
+ Interval(-oo, oo)
118
+ >>> function_range(1/x, x, S.Reals)
119
+ Union(Interval.open(-oo, 0), Interval.open(0, oo))
120
+ >>> function_range(exp(x), x, S.Reals)
121
+ Interval.open(0, oo)
122
+ >>> function_range(log(x), x, S.Reals)
123
+ Interval(-oo, oo)
124
+ >>> function_range(sqrt(x), x, Interval(-5, 9))
125
+ Interval(0, 3)
126
+
127
+ Returns
128
+ =======
129
+
130
+ :py:class:`~.Interval`
131
+ Union of all ranges for all intervals under domain where function is
132
+ continuous.
133
+
134
+ Raises
135
+ ======
136
+
137
+ NotImplementedError
138
+ If any of the intervals, in the given domain, for which function
139
+ is continuous are not finite or real,
140
+ OR if the critical points of the function on the domain cannot be found.
141
+ """
142
+
143
+ if domain is S.EmptySet:
144
+ return S.EmptySet
145
+
146
+ period = periodicity(f, symbol)
147
+ if period == S.Zero:
148
+ # the expression is constant wrt symbol
149
+ return FiniteSet(f.expand())
150
+
151
+ from sympy.series.limits import limit
152
+ from sympy.solvers.solveset import solveset
153
+
154
+ if period is not None:
155
+ if isinstance(domain, Interval):
156
+ if (domain.inf - domain.sup).is_infinite:
157
+ domain = Interval(0, period)
158
+ elif isinstance(domain, Union):
159
+ for sub_dom in domain.args:
160
+ if isinstance(sub_dom, Interval) and \
161
+ ((sub_dom.inf - sub_dom.sup).is_infinite):
162
+ domain = Interval(0, period)
163
+
164
+ intervals = continuous_domain(f, symbol, domain)
165
+ range_int = S.EmptySet
166
+ if isinstance(intervals,(Interval, FiniteSet)):
167
+ interval_iter = (intervals,)
168
+
169
+ elif isinstance(intervals, Union):
170
+ interval_iter = intervals.args
171
+
172
+ else:
173
+ raise NotImplementedError(filldedent('''
174
+ Unable to find range for the given domain.
175
+ '''))
176
+
177
+ for interval in interval_iter:
178
+ if isinstance(interval, FiniteSet):
179
+ for singleton in interval:
180
+ if singleton in domain:
181
+ range_int += FiniteSet(f.subs(symbol, singleton))
182
+ elif isinstance(interval, Interval):
183
+ vals = S.EmptySet
184
+ critical_points = S.EmptySet
185
+ critical_values = S.EmptySet
186
+ bounds = ((interval.left_open, interval.inf, '+'),
187
+ (interval.right_open, interval.sup, '-'))
188
+
189
+ for is_open, limit_point, direction in bounds:
190
+ if is_open:
191
+ critical_values += FiniteSet(limit(f, symbol, limit_point, direction))
192
+ vals += critical_values
193
+
194
+ else:
195
+ vals += FiniteSet(f.subs(symbol, limit_point))
196
+
197
+ solution = solveset(f.diff(symbol), symbol, interval)
198
+
199
+ if not iterable(solution):
200
+ raise NotImplementedError(
201
+ 'Unable to find critical points for {}'.format(f))
202
+ if isinstance(solution, ImageSet):
203
+ raise NotImplementedError(
204
+ 'Infinite number of critical points for {}'.format(f))
205
+
206
+ critical_points += solution
207
+
208
+ for critical_point in critical_points:
209
+ vals += FiniteSet(f.subs(symbol, critical_point))
210
+
211
+ left_open, right_open = False, False
212
+
213
+ if critical_values is not S.EmptySet:
214
+ if critical_values.inf == vals.inf:
215
+ left_open = True
216
+
217
+ if critical_values.sup == vals.sup:
218
+ right_open = True
219
+
220
+ range_int += Interval(vals.inf, vals.sup, left_open, right_open)
221
+ else:
222
+ raise NotImplementedError(filldedent('''
223
+ Unable to find range for the given domain.
224
+ '''))
225
+
226
+ return range_int
227
+
228
+
229
+ def not_empty_in(finset_intersection, *syms):
230
+ """
231
+ Finds the domain of the functions in ``finset_intersection`` in which the
232
+ ``finite_set`` is not-empty.
233
+
234
+ Parameters
235
+ ==========
236
+
237
+ finset_intersection : Intersection of FiniteSet
238
+ The unevaluated intersection of FiniteSet containing
239
+ real-valued functions with Union of Sets
240
+ syms : Tuple of symbols
241
+ Symbol for which domain is to be found
242
+
243
+ Raises
244
+ ======
245
+
246
+ NotImplementedError
247
+ The algorithms to find the non-emptiness of the given FiniteSet are
248
+ not yet implemented.
249
+ ValueError
250
+ The input is not valid.
251
+ RuntimeError
252
+ It is a bug, please report it to the github issue tracker
253
+ (https://github.com/sympy/sympy/issues).
254
+
255
+ Examples
256
+ ========
257
+
258
+ >>> from sympy import FiniteSet, Interval, not_empty_in, oo
259
+ >>> from sympy.abc import x
260
+ >>> not_empty_in(FiniteSet(x/2).intersect(Interval(0, 1)), x)
261
+ Interval(0, 2)
262
+ >>> not_empty_in(FiniteSet(x, x**2).intersect(Interval(1, 2)), x)
263
+ Union(Interval(1, 2), Interval(-sqrt(2), -1))
264
+ >>> not_empty_in(FiniteSet(x**2/(x + 2)).intersect(Interval(1, oo)), x)
265
+ Union(Interval.Lopen(-2, -1), Interval(2, oo))
266
+ """
267
+
268
+ # TODO: handle piecewise defined functions
269
+ # TODO: handle transcendental functions
270
+ # TODO: handle multivariate functions
271
+ if len(syms) == 0:
272
+ raise ValueError("One or more symbols must be given in syms.")
273
+
274
+ if finset_intersection is S.EmptySet:
275
+ return S.EmptySet
276
+
277
+ if isinstance(finset_intersection, Union):
278
+ elm_in_sets = finset_intersection.args[0]
279
+ return Union(not_empty_in(finset_intersection.args[1], *syms),
280
+ elm_in_sets)
281
+
282
+ if isinstance(finset_intersection, FiniteSet):
283
+ finite_set = finset_intersection
284
+ _sets = S.Reals
285
+ else:
286
+ finite_set = finset_intersection.args[1]
287
+ _sets = finset_intersection.args[0]
288
+
289
+ if not isinstance(finite_set, FiniteSet):
290
+ raise ValueError('A FiniteSet must be given, not %s: %s' %
291
+ (type(finite_set), finite_set))
292
+
293
+ if len(syms) == 1:
294
+ symb = syms[0]
295
+ else:
296
+ raise NotImplementedError('more than one variables %s not handled' %
297
+ (syms,))
298
+
299
+ def elm_domain(expr, intrvl):
300
+ """ Finds the domain of an expression in any given interval """
301
+ from sympy.solvers.solveset import solveset
302
+
303
+ _start = intrvl.start
304
+ _end = intrvl.end
305
+ _singularities = solveset(expr.as_numer_denom()[1], symb,
306
+ domain=S.Reals)
307
+
308
+ if intrvl.right_open:
309
+ if _end is S.Infinity:
310
+ _domain1 = S.Reals
311
+ else:
312
+ _domain1 = solveset(expr < _end, symb, domain=S.Reals)
313
+ else:
314
+ _domain1 = solveset(expr <= _end, symb, domain=S.Reals)
315
+
316
+ if intrvl.left_open:
317
+ if _start is S.NegativeInfinity:
318
+ _domain2 = S.Reals
319
+ else:
320
+ _domain2 = solveset(expr > _start, symb, domain=S.Reals)
321
+ else:
322
+ _domain2 = solveset(expr >= _start, symb, domain=S.Reals)
323
+
324
+ # domain in the interval
325
+ expr_with_sing = Intersection(_domain1, _domain2)
326
+ expr_domain = Complement(expr_with_sing, _singularities)
327
+ return expr_domain
328
+
329
+ if isinstance(_sets, Interval):
330
+ return Union(*[elm_domain(element, _sets) for element in finite_set])
331
+
332
+ if isinstance(_sets, Union):
333
+ _domain = S.EmptySet
334
+ for intrvl in _sets.args:
335
+ _domain_element = Union(*[elm_domain(element, intrvl)
336
+ for element in finite_set])
337
+ _domain = Union(_domain, _domain_element)
338
+ return _domain
339
+
340
+
341
+ def periodicity(f, symbol, check=False):
342
+ """
343
+ Tests the given function for periodicity in the given symbol.
344
+
345
+ Parameters
346
+ ==========
347
+
348
+ f : :py:class:`~.Expr`
349
+ The concerned function.
350
+ symbol : :py:class:`~.Symbol`
351
+ The variable for which the period is to be determined.
352
+ check : bool, optional
353
+ The flag to verify whether the value being returned is a period or not.
354
+
355
+ Returns
356
+ =======
357
+
358
+ period
359
+ The period of the function is returned.
360
+ ``None`` is returned when the function is aperiodic or has a complex period.
361
+ The value of $0$ is returned as the period of a constant function.
362
+
363
+ Raises
364
+ ======
365
+
366
+ NotImplementedError
367
+ The value of the period computed cannot be verified.
368
+
369
+
370
+ Notes
371
+ =====
372
+
373
+ Currently, we do not support functions with a complex period.
374
+ The period of functions having complex periodic values such
375
+ as ``exp``, ``sinh`` is evaluated to ``None``.
376
+
377
+ The value returned might not be the "fundamental" period of the given
378
+ function i.e. it may not be the smallest periodic value of the function.
379
+
380
+ The verification of the period through the ``check`` flag is not reliable
381
+ due to internal simplification of the given expression. Hence, it is set
382
+ to ``False`` by default.
383
+
384
+ Examples
385
+ ========
386
+ >>> from sympy import periodicity, Symbol, sin, cos, tan, exp
387
+ >>> x = Symbol('x')
388
+ >>> f = sin(x) + sin(2*x) + sin(3*x)
389
+ >>> periodicity(f, x)
390
+ 2*pi
391
+ >>> periodicity(sin(x)*cos(x), x)
392
+ pi
393
+ >>> periodicity(exp(tan(2*x) - 1), x)
394
+ pi/2
395
+ >>> periodicity(sin(4*x)**cos(2*x), x)
396
+ pi
397
+ >>> periodicity(exp(x), x)
398
+ """
399
+ if symbol.kind is not NumberKind:
400
+ raise NotImplementedError("Cannot use symbol of kind %s" % symbol.kind)
401
+ temp = Dummy('x', real=True)
402
+ f = f.subs(symbol, temp)
403
+ symbol = temp
404
+
405
+ def _check(orig_f, period):
406
+ '''Return the checked period or raise an error.'''
407
+ new_f = orig_f.subs(symbol, symbol + period)
408
+ if new_f.equals(orig_f):
409
+ return period
410
+ else:
411
+ raise NotImplementedError(filldedent('''
412
+ The period of the given function cannot be verified.
413
+ When `%s` was replaced with `%s + %s` in `%s`, the result
414
+ was `%s` which was not recognized as being the same as
415
+ the original function.
416
+ So either the period was wrong or the two forms were
417
+ not recognized as being equal.
418
+ Set check=False to obtain the value.''' %
419
+ (symbol, symbol, period, orig_f, new_f)))
420
+
421
+ orig_f = f
422
+ period = None
423
+
424
+ if isinstance(f, Relational):
425
+ f = f.lhs - f.rhs
426
+
427
+ f = f.simplify()
428
+
429
+ if symbol not in f.free_symbols:
430
+ return S.Zero
431
+
432
+ if isinstance(f, TrigonometricFunction):
433
+ try:
434
+ period = f.period(symbol)
435
+ except NotImplementedError:
436
+ pass
437
+
438
+ if isinstance(f, Abs):
439
+ arg = f.args[0]
440
+ if isinstance(arg, (sec, csc, cos)):
441
+ # all but tan and cot might have a
442
+ # a period that is half as large
443
+ # so recast as sin
444
+ arg = sin(arg.args[0])
445
+ period = periodicity(arg, symbol)
446
+ if period is not None and isinstance(arg, sin):
447
+ # the argument of Abs was a trigonometric other than
448
+ # cot or tan; test to see if the half-period
449
+ # is valid. Abs(arg) has behaviour equivalent to
450
+ # orig_f, so use that for test:
451
+ orig_f = Abs(arg)
452
+ try:
453
+ return _check(orig_f, period/2)
454
+ except NotImplementedError as err:
455
+ if check:
456
+ raise NotImplementedError(err)
457
+ # else let new orig_f and period be
458
+ # checked below
459
+
460
+ if isinstance(f, exp) or (f.is_Pow and f.base == S.Exp1):
461
+ f = Pow(S.Exp1, expand_mul(f.exp))
462
+ if im(f) != 0:
463
+ period_real = periodicity(re(f), symbol)
464
+ period_imag = periodicity(im(f), symbol)
465
+ if period_real is not None and period_imag is not None:
466
+ period = lcim([period_real, period_imag])
467
+
468
+ if f.is_Pow and f.base != S.Exp1:
469
+ base, expo = f.args
470
+ base_has_sym = base.has(symbol)
471
+ expo_has_sym = expo.has(symbol)
472
+
473
+ if base_has_sym and not expo_has_sym:
474
+ period = periodicity(base, symbol)
475
+
476
+ elif expo_has_sym and not base_has_sym:
477
+ period = periodicity(expo, symbol)
478
+
479
+ else:
480
+ period = _periodicity(f.args, symbol)
481
+
482
+ elif f.is_Mul:
483
+ coeff, g = f.as_independent(symbol, as_Add=False)
484
+ if isinstance(g, TrigonometricFunction) or not equal_valued(coeff, 1):
485
+ period = periodicity(g, symbol)
486
+ else:
487
+ period = _periodicity(g.args, symbol)
488
+
489
+ elif f.is_Add:
490
+ k, g = f.as_independent(symbol)
491
+ if k is not S.Zero:
492
+ return periodicity(g, symbol)
493
+
494
+ period = _periodicity(g.args, symbol)
495
+
496
+ elif isinstance(f, Mod):
497
+ a, n = f.args
498
+
499
+ if a == symbol:
500
+ period = n
501
+ elif isinstance(a, TrigonometricFunction):
502
+ period = periodicity(a, symbol)
503
+ #check if 'f' is linear in 'symbol'
504
+ elif (a.is_polynomial(symbol) and degree(a, symbol) == 1 and
505
+ symbol not in n.free_symbols):
506
+ period = Abs(n / a.diff(symbol))
507
+
508
+ elif isinstance(f, Piecewise):
509
+ pass # not handling Piecewise yet as the return type is not favorable
510
+
511
+ elif period is None:
512
+ from sympy.solvers.decompogen import compogen, decompogen
513
+ g_s = decompogen(f, symbol)
514
+ num_of_gs = len(g_s)
515
+ if num_of_gs > 1:
516
+ for index, g in enumerate(reversed(g_s)):
517
+ start_index = num_of_gs - 1 - index
518
+ g = compogen(g_s[start_index:], symbol)
519
+ if g not in (orig_f, f): # Fix for issue 12620
520
+ period = periodicity(g, symbol)
521
+ if period is not None:
522
+ break
523
+
524
+ if period is not None:
525
+ if check:
526
+ return _check(orig_f, period)
527
+ return period
528
+
529
+ return None
530
+
531
+
532
+ def _periodicity(args, symbol):
533
+ """
534
+ Helper for `periodicity` to find the period of a list of simpler
535
+ functions.
536
+ It uses the `lcim` method to find the least common period of
537
+ all the functions.
538
+
539
+ Parameters
540
+ ==========
541
+
542
+ args : Tuple of :py:class:`~.Symbol`
543
+ All the symbols present in a function.
544
+
545
+ symbol : :py:class:`~.Symbol`
546
+ The symbol over which the function is to be evaluated.
547
+
548
+ Returns
549
+ =======
550
+
551
+ period
552
+ The least common period of the function for all the symbols
553
+ of the function.
554
+ ``None`` if for at least one of the symbols the function is aperiodic.
555
+
556
+ """
557
+ periods = []
558
+ for f in args:
559
+ period = periodicity(f, symbol)
560
+ if period is None:
561
+ return None
562
+
563
+ if period is not S.Zero:
564
+ periods.append(period)
565
+
566
+ if len(periods) > 1:
567
+ return lcim(periods)
568
+
569
+ if periods:
570
+ return periods[0]
571
+
572
+
573
+ def lcim(numbers):
574
+ """Returns the least common integral multiple of a list of numbers.
575
+
576
+ The numbers can be rational or irrational or a mixture of both.
577
+ `None` is returned for incommensurable numbers.
578
+
579
+ Parameters
580
+ ==========
581
+
582
+ numbers : list
583
+ Numbers (rational and/or irrational) for which lcim is to be found.
584
+
585
+ Returns
586
+ =======
587
+
588
+ number
589
+ lcim if it exists, otherwise ``None`` for incommensurable numbers.
590
+
591
+ Examples
592
+ ========
593
+
594
+ >>> from sympy.calculus.util import lcim
595
+ >>> from sympy import S, pi
596
+ >>> lcim([S(1)/2, S(3)/4, S(5)/6])
597
+ 15/2
598
+ >>> lcim([2*pi, 3*pi, pi, pi/2])
599
+ 6*pi
600
+ >>> lcim([S(1), 2*pi])
601
+ """
602
+ result = None
603
+ if all(num.is_irrational for num in numbers):
604
+ factorized_nums = [num.factor() for num in numbers]
605
+ factors_num = [num.as_coeff_Mul() for num in factorized_nums]
606
+ term = factors_num[0][1]
607
+ if all(factor == term for coeff, factor in factors_num):
608
+ common_term = term
609
+ coeffs = [coeff for coeff, factor in factors_num]
610
+ result = lcm_list(coeffs) * common_term
611
+
612
+ elif all(num.is_rational for num in numbers):
613
+ result = lcm_list(numbers)
614
+
615
+ else:
616
+ pass
617
+
618
+ return result
619
+
620
+ def is_convex(f, *syms, domain=S.Reals):
621
+ r"""Determines the convexity of the function passed in the argument.
622
+
623
+ Parameters
624
+ ==========
625
+
626
+ f : :py:class:`~.Expr`
627
+ The concerned function.
628
+ syms : Tuple of :py:class:`~.Symbol`
629
+ The variables with respect to which the convexity is to be determined.
630
+ domain : :py:class:`~.Interval`, optional
631
+ The domain over which the convexity of the function has to be checked.
632
+ If unspecified, S.Reals will be the default domain.
633
+
634
+ Returns
635
+ =======
636
+
637
+ bool
638
+ The method returns ``True`` if the function is convex otherwise it
639
+ returns ``False``.
640
+
641
+ Raises
642
+ ======
643
+
644
+ NotImplementedError
645
+ The check for the convexity of multivariate functions is not implemented yet.
646
+
647
+ Notes
648
+ =====
649
+
650
+ To determine concavity of a function pass `-f` as the concerned function.
651
+ To determine logarithmic convexity of a function pass `\log(f)` as
652
+ concerned function.
653
+ To determine logarithmic concavity of a function pass `-\log(f)` as
654
+ concerned function.
655
+
656
+ Currently, convexity check of multivariate functions is not handled.
657
+
658
+ Examples
659
+ ========
660
+
661
+ >>> from sympy import is_convex, symbols, exp, oo, Interval
662
+ >>> x = symbols('x')
663
+ >>> is_convex(exp(x), x)
664
+ True
665
+ >>> is_convex(x**3, x, domain = Interval(-1, oo))
666
+ False
667
+ >>> is_convex(1/x**2, x, domain=Interval.open(0, oo))
668
+ True
669
+
670
+ References
671
+ ==========
672
+
673
+ .. [1] https://en.wikipedia.org/wiki/Convex_function
674
+ .. [2] http://www.ifp.illinois.edu/~angelia/L3_convfunc.pdf
675
+ .. [3] https://en.wikipedia.org/wiki/Logarithmically_convex_function
676
+ .. [4] https://en.wikipedia.org/wiki/Logarithmically_concave_function
677
+ .. [5] https://en.wikipedia.org/wiki/Concave_function
678
+
679
+ """
680
+
681
+ if len(syms) > 1:
682
+ raise NotImplementedError(
683
+ "The check for the convexity of multivariate functions is not implemented yet.")
684
+
685
+ from sympy.solvers.inequalities import solve_univariate_inequality
686
+
687
+ f = _sympify(f)
688
+ var = syms[0]
689
+ if any(s in domain for s in singularities(f, var)):
690
+ return False
691
+
692
+ condition = f.diff(var, 2) < 0
693
+ if solve_univariate_inequality(condition, var, False, domain):
694
+ return False
695
+ return True
696
+
697
+
698
+ def stationary_points(f, symbol, domain=S.Reals):
699
+ """
700
+ Returns the stationary points of a function (where derivative of the
701
+ function is 0) in the given domain.
702
+
703
+ Parameters
704
+ ==========
705
+
706
+ f : :py:class:`~.Expr`
707
+ The concerned function.
708
+ symbol : :py:class:`~.Symbol`
709
+ The variable for which the stationary points are to be determined.
710
+ domain : :py:class:`~.Interval`
711
+ The domain over which the stationary points have to be checked.
712
+ If unspecified, ``S.Reals`` will be the default domain.
713
+
714
+ Returns
715
+ =======
716
+
717
+ Set
718
+ A set of stationary points for the function. If there are no
719
+ stationary point, an :py:class:`~.EmptySet` is returned.
720
+
721
+ Examples
722
+ ========
723
+
724
+ >>> from sympy import Interval, Symbol, S, sin, pi, pprint, stationary_points
725
+ >>> x = Symbol('x')
726
+
727
+ >>> stationary_points(1/x, x, S.Reals)
728
+ EmptySet
729
+
730
+ >>> pprint(stationary_points(sin(x), x), use_unicode=False)
731
+ pi 3*pi
732
+ {2*n*pi + -- | n in Integers} U {2*n*pi + ---- | n in Integers}
733
+ 2 2
734
+
735
+ >>> stationary_points(sin(x),x, Interval(0, 4*pi))
736
+ {pi/2, 3*pi/2, 5*pi/2, 7*pi/2}
737
+
738
+ """
739
+ from sympy.solvers.solveset import solveset
740
+
741
+ if domain is S.EmptySet:
742
+ return S.EmptySet
743
+
744
+ domain = continuous_domain(f, symbol, domain)
745
+ set = solveset(diff(f, symbol), symbol, domain)
746
+
747
+ return set
748
+
749
+
750
+ def maximum(f, symbol, domain=S.Reals):
751
+ """
752
+ Returns the maximum value of a function in the given domain.
753
+
754
+ Parameters
755
+ ==========
756
+
757
+ f : :py:class:`~.Expr`
758
+ The concerned function.
759
+ symbol : :py:class:`~.Symbol`
760
+ The variable for maximum value needs to be determined.
761
+ domain : :py:class:`~.Interval`
762
+ The domain over which the maximum have to be checked.
763
+ If unspecified, then the global maximum is returned.
764
+
765
+ Returns
766
+ =======
767
+
768
+ number
769
+ Maximum value of the function in given domain.
770
+
771
+ Examples
772
+ ========
773
+
774
+ >>> from sympy import Interval, Symbol, S, sin, cos, pi, maximum
775
+ >>> x = Symbol('x')
776
+
777
+ >>> f = -x**2 + 2*x + 5
778
+ >>> maximum(f, x, S.Reals)
779
+ 6
780
+
781
+ >>> maximum(sin(x), x, Interval(-pi, pi/4))
782
+ sqrt(2)/2
783
+
784
+ >>> maximum(sin(x)*cos(x), x)
785
+ 1/2
786
+
787
+ """
788
+ if isinstance(symbol, Symbol):
789
+ if domain is S.EmptySet:
790
+ raise ValueError("Maximum value not defined for empty domain.")
791
+
792
+ return function_range(f, symbol, domain).sup
793
+ else:
794
+ raise ValueError("%s is not a valid symbol." % symbol)
795
+
796
+
797
+ def minimum(f, symbol, domain=S.Reals):
798
+ """
799
+ Returns the minimum value of a function in the given domain.
800
+
801
+ Parameters
802
+ ==========
803
+
804
+ f : :py:class:`~.Expr`
805
+ The concerned function.
806
+ symbol : :py:class:`~.Symbol`
807
+ The variable for minimum value needs to be determined.
808
+ domain : :py:class:`~.Interval`
809
+ The domain over which the minimum have to be checked.
810
+ If unspecified, then the global minimum is returned.
811
+
812
+ Returns
813
+ =======
814
+
815
+ number
816
+ Minimum value of the function in the given domain.
817
+
818
+ Examples
819
+ ========
820
+
821
+ >>> from sympy import Interval, Symbol, S, sin, cos, minimum
822
+ >>> x = Symbol('x')
823
+
824
+ >>> f = x**2 + 2*x + 5
825
+ >>> minimum(f, x, S.Reals)
826
+ 4
827
+
828
+ >>> minimum(sin(x), x, Interval(2, 3))
829
+ sin(3)
830
+
831
+ >>> minimum(sin(x)*cos(x), x)
832
+ -1/2
833
+
834
+ """
835
+ if isinstance(symbol, Symbol):
836
+ if domain is S.EmptySet:
837
+ raise ValueError("Minimum value not defined for empty domain.")
838
+
839
+ return function_range(f, symbol, domain).inf
840
+ else:
841
+ raise ValueError("%s is not a valid symbol." % symbol)
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__init__.py ADDED
@@ -0,0 +1,18 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ r"""
2
+ The :py:mod:`~sympy.holonomic` module is intended to deal with holonomic functions along
3
+ with various operations on them like addition, multiplication, composition,
4
+ integration and differentiation. The module also implements various kinds of
5
+ conversions such as converting holonomic functions to a different form and the
6
+ other way around.
7
+ """
8
+
9
+ from .holonomic import (DifferentialOperator, HolonomicFunction, DifferentialOperators,
10
+ from_hyper, from_meijerg, expr_to_holonomic)
11
+ from .recurrence import RecurrenceOperators, RecurrenceOperator, HolonomicSequence
12
+
13
+ __all__ = [
14
+ 'DifferentialOperator', 'HolonomicFunction', 'DifferentialOperators',
15
+ 'from_hyper', 'from_meijerg', 'expr_to_holonomic',
16
+
17
+ 'RecurrenceOperators', 'RecurrenceOperator', 'HolonomicSequence',
18
+ ]
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/__init__.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/holonomic/__pycache__/holonomic.cpython-310.pyc ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/holonomic/holonomic.py ADDED
@@ -0,0 +1,2899 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ This module implements Holonomic Functions and
3
+ various operations on them.
4
+ """
5
+
6
+ from sympy.core import Add, Mul, Pow
7
+ from sympy.core.numbers import (NaN, Infinity, NegativeInfinity, Float, I, pi,
8
+ equal_valued)
9
+ from sympy.core.singleton import S
10
+ from sympy.core.sorting import ordered
11
+ from sympy.core.symbol import Dummy, Symbol
12
+ from sympy.core.sympify import sympify
13
+ from sympy.functions.combinatorial.factorials import binomial, factorial, rf
14
+ from sympy.functions.elementary.exponential import exp_polar, exp, log
15
+ from sympy.functions.elementary.hyperbolic import (cosh, sinh)
16
+ from sympy.functions.elementary.miscellaneous import sqrt
17
+ from sympy.functions.elementary.trigonometric import (cos, sin, sinc)
18
+ from sympy.functions.special.error_functions import (Ci, Shi, Si, erf, erfc, erfi)
19
+ from sympy.functions.special.gamma_functions import gamma
20
+ from sympy.functions.special.hyper import hyper, meijerg
21
+ from sympy.integrals import meijerint
22
+ from sympy.matrices import Matrix
23
+ from sympy.polys.rings import PolyElement
24
+ from sympy.polys.fields import FracElement
25
+ from sympy.polys.domains import QQ, RR
26
+ from sympy.polys.polyclasses import DMF
27
+ from sympy.polys.polyroots import roots
28
+ from sympy.polys.polytools import Poly
29
+ from sympy.polys.matrices import DomainMatrix
30
+ from sympy.printing import sstr
31
+ from sympy.series.limits import limit
32
+ from sympy.series.order import Order
33
+ from sympy.simplify.hyperexpand import hyperexpand
34
+ from sympy.simplify.simplify import nsimplify
35
+ from sympy.solvers.solvers import solve
36
+
37
+ from .recurrence import HolonomicSequence, RecurrenceOperator, RecurrenceOperators
38
+ from .holonomicerrors import (NotPowerSeriesError, NotHyperSeriesError,
39
+ SingularityError, NotHolonomicError)
40
+
41
+
42
+ def _find_nonzero_solution(r, homosys):
43
+ ones = lambda shape: DomainMatrix.ones(shape, r.domain)
44
+ particular, nullspace = r._solve(homosys)
45
+ nullity = nullspace.shape[0]
46
+ nullpart = ones((1, nullity)) * nullspace
47
+ sol = (particular + nullpart).transpose()
48
+ return sol
49
+
50
+
51
+
52
+ def DifferentialOperators(base, generator):
53
+ r"""
54
+ This function is used to create annihilators using ``Dx``.
55
+
56
+ Explanation
57
+ ===========
58
+
59
+ Returns an Algebra of Differential Operators also called Weyl Algebra
60
+ and the operator for differentiation i.e. the ``Dx`` operator.
61
+
62
+ Parameters
63
+ ==========
64
+
65
+ base:
66
+ Base polynomial ring for the algebra.
67
+ The base polynomial ring is the ring of polynomials in :math:`x` that
68
+ will appear as coefficients in the operators.
69
+ generator:
70
+ Generator of the algebra which can
71
+ be either a noncommutative ``Symbol`` or a string. e.g. "Dx" or "D".
72
+
73
+ Examples
74
+ ========
75
+
76
+ >>> from sympy import ZZ
77
+ >>> from sympy.abc import x
78
+ >>> from sympy.holonomic.holonomic import DifferentialOperators
79
+ >>> R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
80
+ >>> R
81
+ Univariate Differential Operator Algebra in intermediate Dx over the base ring ZZ[x]
82
+ >>> Dx*x
83
+ (1) + (x)*Dx
84
+ """
85
+
86
+ ring = DifferentialOperatorAlgebra(base, generator)
87
+ return (ring, ring.derivative_operator)
88
+
89
+
90
+ class DifferentialOperatorAlgebra:
91
+ r"""
92
+ An Ore Algebra is a set of noncommutative polynomials in the
93
+ intermediate ``Dx`` and coefficients in a base polynomial ring :math:`A`.
94
+ It follows the commutation rule:
95
+
96
+ .. math ::
97
+ Dxa = \sigma(a)Dx + \delta(a)
98
+
99
+ for :math:`a \subset A`.
100
+
101
+ Where :math:`\sigma: A \Rightarrow A` is an endomorphism and :math:`\delta: A \rightarrow A`
102
+ is a skew-derivation i.e. :math:`\delta(ab) = \delta(a) b + \sigma(a) \delta(b)`.
103
+
104
+ If one takes the sigma as identity map and delta as the standard derivation
105
+ then it becomes the algebra of Differential Operators also called
106
+ a Weyl Algebra i.e. an algebra whose elements are Differential Operators.
107
+
108
+ This class represents a Weyl Algebra and serves as the parent ring for
109
+ Differential Operators.
110
+
111
+ Examples
112
+ ========
113
+
114
+ >>> from sympy import ZZ
115
+ >>> from sympy import symbols
116
+ >>> from sympy.holonomic.holonomic import DifferentialOperators
117
+ >>> x = symbols('x')
118
+ >>> R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
119
+ >>> R
120
+ Univariate Differential Operator Algebra in intermediate Dx over the base ring
121
+ ZZ[x]
122
+
123
+ See Also
124
+ ========
125
+
126
+ DifferentialOperator
127
+ """
128
+
129
+ def __init__(self, base, generator):
130
+ # the base polynomial ring for the algebra
131
+ self.base = base
132
+ # the operator representing differentiation i.e. `Dx`
133
+ self.derivative_operator = DifferentialOperator(
134
+ [base.zero, base.one], self)
135
+
136
+ if generator is None:
137
+ self.gen_symbol = Symbol('Dx', commutative=False)
138
+ else:
139
+ if isinstance(generator, str):
140
+ self.gen_symbol = Symbol(generator, commutative=False)
141
+ elif isinstance(generator, Symbol):
142
+ self.gen_symbol = generator
143
+
144
+ def __str__(self):
145
+ string = 'Univariate Differential Operator Algebra in intermediate '\
146
+ + sstr(self.gen_symbol) + ' over the base ring ' + \
147
+ (self.base).__str__()
148
+
149
+ return string
150
+
151
+ __repr__ = __str__
152
+
153
+ def __eq__(self, other):
154
+ if self.base == other.base and self.gen_symbol == other.gen_symbol:
155
+ return True
156
+ else:
157
+ return False
158
+
159
+
160
+ class DifferentialOperator:
161
+ """
162
+ Differential Operators are elements of Weyl Algebra. The Operators
163
+ are defined by a list of polynomials in the base ring and the
164
+ parent ring of the Operator i.e. the algebra it belongs to.
165
+
166
+ Explanation
167
+ ===========
168
+
169
+ Takes a list of polynomials for each power of ``Dx`` and the
170
+ parent ring which must be an instance of DifferentialOperatorAlgebra.
171
+
172
+ A Differential Operator can be created easily using
173
+ the operator ``Dx``. See examples below.
174
+
175
+ Examples
176
+ ========
177
+
178
+ >>> from sympy.holonomic.holonomic import DifferentialOperator, DifferentialOperators
179
+ >>> from sympy import ZZ
180
+ >>> from sympy import symbols
181
+ >>> x = symbols('x')
182
+ >>> R, Dx = DifferentialOperators(ZZ.old_poly_ring(x),'Dx')
183
+
184
+ >>> DifferentialOperator([0, 1, x**2], R)
185
+ (1)*Dx + (x**2)*Dx**2
186
+
187
+ >>> (x*Dx*x + 1 - Dx**2)**2
188
+ (2*x**2 + 2*x + 1) + (4*x**3 + 2*x**2 - 4)*Dx + (x**4 - 6*x - 2)*Dx**2 + (-2*x**2)*Dx**3 + (1)*Dx**4
189
+
190
+ See Also
191
+ ========
192
+
193
+ DifferentialOperatorAlgebra
194
+ """
195
+
196
+ _op_priority = 20
197
+
198
+ def __init__(self, list_of_poly, parent):
199
+ """
200
+ Parameters
201
+ ==========
202
+
203
+ list_of_poly:
204
+ List of polynomials belonging to the base ring of the algebra.
205
+ parent:
206
+ Parent algebra of the operator.
207
+ """
208
+
209
+ # the parent ring for this operator
210
+ # must be an DifferentialOperatorAlgebra object
211
+ self.parent = parent
212
+ base = self.parent.base
213
+ self.x = base.gens[0] if isinstance(base.gens[0], Symbol) else base.gens[0][0]
214
+ # sequence of polynomials in x for each power of Dx
215
+ # the list should not have trailing zeroes
216
+ # represents the operator
217
+ # convert the expressions into ring elements using from_sympy
218
+ for i, j in enumerate(list_of_poly):
219
+ if not isinstance(j, base.dtype):
220
+ list_of_poly[i] = base.from_sympy(sympify(j))
221
+ else:
222
+ list_of_poly[i] = base.from_sympy(base.to_sympy(j))
223
+
224
+ self.listofpoly = list_of_poly
225
+ # highest power of `Dx`
226
+ self.order = len(self.listofpoly) - 1
227
+
228
+ def __mul__(self, other):
229
+ """
230
+ Multiplies two DifferentialOperator and returns another
231
+ DifferentialOperator instance using the commutation rule
232
+ Dx*a = a*Dx + a'
233
+ """
234
+
235
+ listofself = self.listofpoly
236
+
237
+ if not isinstance(other, DifferentialOperator):
238
+ if not isinstance(other, self.parent.base.dtype):
239
+ listofother = [self.parent.base.from_sympy(sympify(other))]
240
+
241
+ else:
242
+ listofother = [other]
243
+ else:
244
+ listofother = other.listofpoly
245
+
246
+ # multiplies a polynomial `b` with a list of polynomials
247
+ def _mul_dmp_diffop(b, listofother):
248
+ if isinstance(listofother, list):
249
+ sol = []
250
+ for i in listofother:
251
+ sol.append(i * b)
252
+ return sol
253
+ else:
254
+ return [b * listofother]
255
+
256
+ sol = _mul_dmp_diffop(listofself[0], listofother)
257
+
258
+ # compute Dx^i * b
259
+ def _mul_Dxi_b(b):
260
+ sol1 = [self.parent.base.zero]
261
+ sol2 = []
262
+
263
+ if isinstance(b, list):
264
+ for i in b:
265
+ sol1.append(i)
266
+ sol2.append(i.diff())
267
+ else:
268
+ sol1.append(self.parent.base.from_sympy(b))
269
+ sol2.append(self.parent.base.from_sympy(b).diff())
270
+
271
+ return _add_lists(sol1, sol2)
272
+
273
+ for i in range(1, len(listofself)):
274
+ # find Dx^i * b in ith iteration
275
+ listofother = _mul_Dxi_b(listofother)
276
+ # solution = solution + listofself[i] * (Dx^i * b)
277
+ sol = _add_lists(sol, _mul_dmp_diffop(listofself[i], listofother))
278
+
279
+ return DifferentialOperator(sol, self.parent)
280
+
281
+ def __rmul__(self, other):
282
+ if not isinstance(other, DifferentialOperator):
283
+
284
+ if not isinstance(other, self.parent.base.dtype):
285
+ other = (self.parent.base).from_sympy(sympify(other))
286
+
287
+ sol = []
288
+ for j in self.listofpoly:
289
+ sol.append(other * j)
290
+
291
+ return DifferentialOperator(sol, self.parent)
292
+
293
+ def __add__(self, other):
294
+ if isinstance(other, DifferentialOperator):
295
+
296
+ sol = _add_lists(self.listofpoly, other.listofpoly)
297
+ return DifferentialOperator(sol, self.parent)
298
+
299
+ else:
300
+ list_self = self.listofpoly
301
+ if not isinstance(other, self.parent.base.dtype):
302
+ list_other = [((self.parent).base).from_sympy(sympify(other))]
303
+ else:
304
+ list_other = [other]
305
+ sol = []
306
+ sol.append(list_self[0] + list_other[0])
307
+ sol += list_self[1:]
308
+
309
+ return DifferentialOperator(sol, self.parent)
310
+
311
+ __radd__ = __add__
312
+
313
+ def __sub__(self, other):
314
+ return self + (-1) * other
315
+
316
+ def __rsub__(self, other):
317
+ return (-1) * self + other
318
+
319
+ def __neg__(self):
320
+ return -1 * self
321
+
322
+ def __truediv__(self, other):
323
+ return self * (S.One / other)
324
+
325
+ def __pow__(self, n):
326
+ if n == 1:
327
+ return self
328
+ if n == 0:
329
+ return DifferentialOperator([self.parent.base.one], self.parent)
330
+
331
+ # if self is `Dx`
332
+ if self.listofpoly == self.parent.derivative_operator.listofpoly:
333
+ sol = [self.parent.base.zero]*n
334
+ sol.append(self.parent.base.one)
335
+ return DifferentialOperator(sol, self.parent)
336
+
337
+ # the general case
338
+ else:
339
+ if n % 2 == 1:
340
+ powreduce = self**(n - 1)
341
+ return powreduce * self
342
+ elif n % 2 == 0:
343
+ powreduce = self**(n / 2)
344
+ return powreduce * powreduce
345
+
346
+ def __str__(self):
347
+ listofpoly = self.listofpoly
348
+ print_str = ''
349
+
350
+ for i, j in enumerate(listofpoly):
351
+ if j == self.parent.base.zero:
352
+ continue
353
+
354
+ if i == 0:
355
+ print_str += '(' + sstr(j) + ')'
356
+ continue
357
+
358
+ if print_str:
359
+ print_str += ' + '
360
+
361
+ if i == 1:
362
+ print_str += '(' + sstr(j) + ')*%s' %(self.parent.gen_symbol)
363
+ continue
364
+
365
+ print_str += '(' + sstr(j) + ')' + '*%s**' %(self.parent.gen_symbol) + sstr(i)
366
+
367
+ return print_str
368
+
369
+ __repr__ = __str__
370
+
371
+ def __eq__(self, other):
372
+ if isinstance(other, DifferentialOperator):
373
+ if self.listofpoly == other.listofpoly and self.parent == other.parent:
374
+ return True
375
+ else:
376
+ return False
377
+ else:
378
+ if self.listofpoly[0] == other:
379
+ for i in self.listofpoly[1:]:
380
+ if i is not self.parent.base.zero:
381
+ return False
382
+ return True
383
+ else:
384
+ return False
385
+
386
+ def is_singular(self, x0):
387
+ """
388
+ Checks if the differential equation is singular at x0.
389
+ """
390
+
391
+ base = self.parent.base
392
+ return x0 in roots(base.to_sympy(self.listofpoly[-1]), self.x)
393
+
394
+
395
+ class HolonomicFunction:
396
+ r"""
397
+ A Holonomic Function is a solution to a linear homogeneous ordinary
398
+ differential equation with polynomial coefficients. This differential
399
+ equation can also be represented by an annihilator i.e. a Differential
400
+ Operator ``L`` such that :math:`L.f = 0`. For uniqueness of these functions,
401
+ initial conditions can also be provided along with the annihilator.
402
+
403
+ Explanation
404
+ ===========
405
+
406
+ Holonomic functions have closure properties and thus forms a ring.
407
+ Given two Holonomic Functions f and g, their sum, product,
408
+ integral and derivative is also a Holonomic Function.
409
+
410
+ For ordinary points initial condition should be a vector of values of
411
+ the derivatives i.e. :math:`[y(x_0), y'(x_0), y''(x_0) ... ]`.
412
+
413
+ For regular singular points initial conditions can also be provided in this
414
+ format:
415
+ :math:`{s0: [C_0, C_1, ...], s1: [C^1_0, C^1_1, ...], ...}`
416
+ where s0, s1, ... are the roots of indicial equation and vectors
417
+ :math:`[C_0, C_1, ...], [C^0_0, C^0_1, ...], ...` are the corresponding initial
418
+ terms of the associated power series. See Examples below.
419
+
420
+ Examples
421
+ ========
422
+
423
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
424
+ >>> from sympy import QQ
425
+ >>> from sympy import symbols, S
426
+ >>> x = symbols('x')
427
+ >>> R, Dx = DifferentialOperators(QQ.old_poly_ring(x),'Dx')
428
+
429
+ >>> p = HolonomicFunction(Dx - 1, x, 0, [1]) # e^x
430
+ >>> q = HolonomicFunction(Dx**2 + 1, x, 0, [0, 1]) # sin(x)
431
+
432
+ >>> p + q # annihilator of e^x + sin(x)
433
+ HolonomicFunction((-1) + (1)*Dx + (-1)*Dx**2 + (1)*Dx**3, x, 0, [1, 2, 1])
434
+
435
+ >>> p * q # annihilator of e^x * sin(x)
436
+ HolonomicFunction((2) + (-2)*Dx + (1)*Dx**2, x, 0, [0, 1])
437
+
438
+ An example of initial conditions for regular singular points,
439
+ the indicial equation has only one root `1/2`.
440
+
441
+ >>> HolonomicFunction(-S(1)/2 + x*Dx, x, 0, {S(1)/2: [1]})
442
+ HolonomicFunction((-1/2) + (x)*Dx, x, 0, {1/2: [1]})
443
+
444
+ >>> HolonomicFunction(-S(1)/2 + x*Dx, x, 0, {S(1)/2: [1]}).to_expr()
445
+ sqrt(x)
446
+
447
+ To plot a Holonomic Function, one can use `.evalf()` for numerical
448
+ computation. Here's an example on `sin(x)**2/x` using numpy and matplotlib.
449
+
450
+ >>> import sympy.holonomic # doctest: +SKIP
451
+ >>> from sympy import var, sin # doctest: +SKIP
452
+ >>> import matplotlib.pyplot as plt # doctest: +SKIP
453
+ >>> import numpy as np # doctest: +SKIP
454
+ >>> var("x") # doctest: +SKIP
455
+ >>> r = np.linspace(1, 5, 100) # doctest: +SKIP
456
+ >>> y = sympy.holonomic.expr_to_holonomic(sin(x)**2/x, x0=1).evalf(r) # doctest: +SKIP
457
+ >>> plt.plot(r, y, label="holonomic function") # doctest: +SKIP
458
+ >>> plt.show() # doctest: +SKIP
459
+
460
+ """
461
+
462
+ _op_priority = 20
463
+
464
+ def __init__(self, annihilator, x, x0=0, y0=None):
465
+ """
466
+
467
+ Parameters
468
+ ==========
469
+
470
+ annihilator:
471
+ Annihilator of the Holonomic Function, represented by a
472
+ `DifferentialOperator` object.
473
+ x:
474
+ Variable of the function.
475
+ x0:
476
+ The point at which initial conditions are stored.
477
+ Generally an integer.
478
+ y0:
479
+ The initial condition. The proper format for the initial condition
480
+ is described in class docstring. To make the function unique,
481
+ length of the vector `y0` should be equal to or greater than the
482
+ order of differential equation.
483
+ """
484
+
485
+ # initial condition
486
+ self.y0 = y0
487
+ # the point for initial conditions, default is zero.
488
+ self.x0 = x0
489
+ # differential operator L such that L.f = 0
490
+ self.annihilator = annihilator
491
+ self.x = x
492
+
493
+ def __str__(self):
494
+ if self._have_init_cond():
495
+ str_sol = 'HolonomicFunction(%s, %s, %s, %s)' % (str(self.annihilator),\
496
+ sstr(self.x), sstr(self.x0), sstr(self.y0))
497
+ else:
498
+ str_sol = 'HolonomicFunction(%s, %s)' % (str(self.annihilator),\
499
+ sstr(self.x))
500
+
501
+ return str_sol
502
+
503
+ __repr__ = __str__
504
+
505
+ def unify(self, other):
506
+ """
507
+ Unifies the base polynomial ring of a given two Holonomic
508
+ Functions.
509
+ """
510
+
511
+ R1 = self.annihilator.parent.base
512
+ R2 = other.annihilator.parent.base
513
+
514
+ dom1 = R1.dom
515
+ dom2 = R2.dom
516
+
517
+ if R1 == R2:
518
+ return (self, other)
519
+
520
+ R = (dom1.unify(dom2)).old_poly_ring(self.x)
521
+
522
+ newparent, _ = DifferentialOperators(R, str(self.annihilator.parent.gen_symbol))
523
+
524
+ sol1 = [R1.to_sympy(i) for i in self.annihilator.listofpoly]
525
+ sol2 = [R2.to_sympy(i) for i in other.annihilator.listofpoly]
526
+
527
+ sol1 = DifferentialOperator(sol1, newparent)
528
+ sol2 = DifferentialOperator(sol2, newparent)
529
+
530
+ sol1 = HolonomicFunction(sol1, self.x, self.x0, self.y0)
531
+ sol2 = HolonomicFunction(sol2, other.x, other.x0, other.y0)
532
+
533
+ return (sol1, sol2)
534
+
535
+ def is_singularics(self):
536
+ """
537
+ Returns True if the function have singular initial condition
538
+ in the dictionary format.
539
+
540
+ Returns False if the function have ordinary initial condition
541
+ in the list format.
542
+
543
+ Returns None for all other cases.
544
+ """
545
+
546
+ if isinstance(self.y0, dict):
547
+ return True
548
+ elif isinstance(self.y0, list):
549
+ return False
550
+
551
+ def _have_init_cond(self):
552
+ """
553
+ Checks if the function have initial condition.
554
+ """
555
+ return bool(self.y0)
556
+
557
+ def _singularics_to_ord(self):
558
+ """
559
+ Converts a singular initial condition to ordinary if possible.
560
+ """
561
+ a = list(self.y0)[0]
562
+ b = self.y0[a]
563
+
564
+ if len(self.y0) == 1 and a == int(a) and a > 0:
565
+ y0 = []
566
+ a = int(a)
567
+ for i in range(a):
568
+ y0.append(S.Zero)
569
+ y0 += [j * factorial(a + i) for i, j in enumerate(b)]
570
+
571
+ return HolonomicFunction(self.annihilator, self.x, self.x0, y0)
572
+
573
+ def __add__(self, other):
574
+ # if the ground domains are different
575
+ if self.annihilator.parent.base != other.annihilator.parent.base:
576
+ a, b = self.unify(other)
577
+ return a + b
578
+
579
+ deg1 = self.annihilator.order
580
+ deg2 = other.annihilator.order
581
+ dim = max(deg1, deg2)
582
+ R = self.annihilator.parent.base
583
+ K = R.get_field()
584
+
585
+ rowsself = [self.annihilator]
586
+ rowsother = [other.annihilator]
587
+ gen = self.annihilator.parent.derivative_operator
588
+
589
+ # constructing annihilators up to order dim
590
+ for i in range(dim - deg1):
591
+ diff1 = (gen * rowsself[-1])
592
+ rowsself.append(diff1)
593
+
594
+ for i in range(dim - deg2):
595
+ diff2 = (gen * rowsother[-1])
596
+ rowsother.append(diff2)
597
+
598
+ row = rowsself + rowsother
599
+
600
+ # constructing the matrix of the ansatz
601
+ r = []
602
+
603
+ for expr in row:
604
+ p = []
605
+ for i in range(dim + 1):
606
+ if i >= len(expr.listofpoly):
607
+ p.append(K.zero)
608
+ else:
609
+ p.append(K.new(expr.listofpoly[i].rep))
610
+ r.append(p)
611
+
612
+ # solving the linear system using gauss jordan solver
613
+ r = DomainMatrix(r, (len(row), dim+1), K).transpose()
614
+ homosys = DomainMatrix.zeros((dim+1, 1), K)
615
+ sol = _find_nonzero_solution(r, homosys)
616
+
617
+ # if a solution is not obtained then increasing the order by 1 in each
618
+ # iteration
619
+ while sol.is_zero_matrix:
620
+ dim += 1
621
+
622
+ diff1 = (gen * rowsself[-1])
623
+ rowsself.append(diff1)
624
+
625
+ diff2 = (gen * rowsother[-1])
626
+ rowsother.append(diff2)
627
+
628
+ row = rowsself + rowsother
629
+ r = []
630
+
631
+ for expr in row:
632
+ p = []
633
+ for i in range(dim + 1):
634
+ if i >= len(expr.listofpoly):
635
+ p.append(K.zero)
636
+ else:
637
+ p.append(K.new(expr.listofpoly[i].rep))
638
+ r.append(p)
639
+
640
+ # solving the linear system using gauss jordan solver
641
+ r = DomainMatrix(r, (len(row), dim+1), K).transpose()
642
+ homosys = DomainMatrix.zeros((dim+1, 1), K)
643
+ sol = _find_nonzero_solution(r, homosys)
644
+
645
+ # taking only the coefficients needed to multiply with `self`
646
+ # can be also be done the other way by taking R.H.S and multiplying with
647
+ # `other`
648
+ sol = sol.flat()[:dim + 1 - deg1]
649
+ sol1 = _normalize(sol, self.annihilator.parent)
650
+ # annihilator of the solution
651
+ sol = sol1 * (self.annihilator)
652
+ sol = _normalize(sol.listofpoly, self.annihilator.parent, negative=False)
653
+
654
+ if not (self._have_init_cond() and other._have_init_cond()):
655
+ return HolonomicFunction(sol, self.x)
656
+
657
+ # both the functions have ordinary initial conditions
658
+ if self.is_singularics() == False and other.is_singularics() == False:
659
+
660
+ # directly add the corresponding value
661
+ if self.x0 == other.x0:
662
+ # try to extended the initial conditions
663
+ # using the annihilator
664
+ y1 = _extend_y0(self, sol.order)
665
+ y2 = _extend_y0(other, sol.order)
666
+ y0 = [a + b for a, b in zip(y1, y2)]
667
+ return HolonomicFunction(sol, self.x, self.x0, y0)
668
+
669
+ else:
670
+ # change the initial conditions to a same point
671
+ selfat0 = self.annihilator.is_singular(0)
672
+ otherat0 = other.annihilator.is_singular(0)
673
+
674
+ if self.x0 == 0 and not selfat0 and not otherat0:
675
+ return self + other.change_ics(0)
676
+
677
+ elif other.x0 == 0 and not selfat0 and not otherat0:
678
+ return self.change_ics(0) + other
679
+
680
+ else:
681
+ selfatx0 = self.annihilator.is_singular(self.x0)
682
+ otheratx0 = other.annihilator.is_singular(self.x0)
683
+
684
+ if not selfatx0 and not otheratx0:
685
+ return self + other.change_ics(self.x0)
686
+
687
+ else:
688
+ return self.change_ics(other.x0) + other
689
+
690
+ if self.x0 != other.x0:
691
+ return HolonomicFunction(sol, self.x)
692
+
693
+ # if the functions have singular_ics
694
+ y1 = None
695
+ y2 = None
696
+
697
+ if self.is_singularics() == False and other.is_singularics() == True:
698
+ # convert the ordinary initial condition to singular.
699
+ _y0 = [j / factorial(i) for i, j in enumerate(self.y0)]
700
+ y1 = {S.Zero: _y0}
701
+ y2 = other.y0
702
+ elif self.is_singularics() == True and other.is_singularics() == False:
703
+ _y0 = [j / factorial(i) for i, j in enumerate(other.y0)]
704
+ y1 = self.y0
705
+ y2 = {S.Zero: _y0}
706
+ elif self.is_singularics() == True and other.is_singularics() == True:
707
+ y1 = self.y0
708
+ y2 = other.y0
709
+
710
+ # computing singular initial condition for the result
711
+ # taking union of the series terms of both functions
712
+ y0 = {}
713
+ for i in y1:
714
+ # add corresponding initial terms if the power
715
+ # on `x` is same
716
+ if i in y2:
717
+ y0[i] = [a + b for a, b in zip(y1[i], y2[i])]
718
+ else:
719
+ y0[i] = y1[i]
720
+ for i in y2:
721
+ if i not in y1:
722
+ y0[i] = y2[i]
723
+ return HolonomicFunction(sol, self.x, self.x0, y0)
724
+
725
+ def integrate(self, limits, initcond=False):
726
+ """
727
+ Integrates the given holonomic function.
728
+
729
+ Examples
730
+ ========
731
+
732
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
733
+ >>> from sympy import QQ
734
+ >>> from sympy import symbols
735
+ >>> x = symbols('x')
736
+ >>> R, Dx = DifferentialOperators(QQ.old_poly_ring(x),'Dx')
737
+ >>> HolonomicFunction(Dx - 1, x, 0, [1]).integrate((x, 0, x)) # e^x - 1
738
+ HolonomicFunction((-1)*Dx + (1)*Dx**2, x, 0, [0, 1])
739
+ >>> HolonomicFunction(Dx**2 + 1, x, 0, [1, 0]).integrate((x, 0, x))
740
+ HolonomicFunction((1)*Dx + (1)*Dx**3, x, 0, [0, 1, 0])
741
+ """
742
+
743
+ # to get the annihilator, just multiply by Dx from right
744
+ D = self.annihilator.parent.derivative_operator
745
+
746
+ # if the function have initial conditions of the series format
747
+ if self.is_singularics() == True:
748
+
749
+ r = self._singularics_to_ord()
750
+ if r:
751
+ return r.integrate(limits, initcond=initcond)
752
+
753
+ # computing singular initial condition for the function
754
+ # produced after integration.
755
+ y0 = {}
756
+ for i in self.y0:
757
+ c = self.y0[i]
758
+ c2 = []
759
+ for j, cj in enumerate(c):
760
+ if cj == 0:
761
+ c2.append(S.Zero)
762
+
763
+ # if power on `x` is -1, the integration becomes log(x)
764
+ # TODO: Implement this case
765
+ elif i + j + 1 == 0:
766
+ raise NotImplementedError("logarithmic terms in the series are not supported")
767
+ else:
768
+ c2.append(cj / S(i + j + 1))
769
+ y0[i + 1] = c2
770
+
771
+ if hasattr(limits, "__iter__"):
772
+ raise NotImplementedError("Definite integration for singular initial conditions")
773
+
774
+ return HolonomicFunction(self.annihilator * D, self.x, self.x0, y0)
775
+
776
+ # if no initial conditions are available for the function
777
+ if not self._have_init_cond():
778
+ if initcond:
779
+ return HolonomicFunction(self.annihilator * D, self.x, self.x0, [S.Zero])
780
+ return HolonomicFunction(self.annihilator * D, self.x)
781
+
782
+ # definite integral
783
+ # initial conditions for the answer will be stored at point `a`,
784
+ # where `a` is the lower limit of the integrand
785
+ if hasattr(limits, "__iter__"):
786
+
787
+ if len(limits) == 3 and limits[0] == self.x:
788
+ x0 = self.x0
789
+ a = limits[1]
790
+ b = limits[2]
791
+ definite = True
792
+
793
+ else:
794
+ definite = False
795
+
796
+ y0 = [S.Zero]
797
+ y0 += self.y0
798
+
799
+ indefinite_integral = HolonomicFunction(self.annihilator * D, self.x, self.x0, y0)
800
+
801
+ if not definite:
802
+ return indefinite_integral
803
+
804
+ # use evalf to get the values at `a`
805
+ if x0 != a:
806
+ try:
807
+ indefinite_expr = indefinite_integral.to_expr()
808
+ except (NotHyperSeriesError, NotPowerSeriesError):
809
+ indefinite_expr = None
810
+
811
+ if indefinite_expr:
812
+ lower = indefinite_expr.subs(self.x, a)
813
+ if isinstance(lower, NaN):
814
+ lower = indefinite_expr.limit(self.x, a)
815
+ else:
816
+ lower = indefinite_integral.evalf(a)
817
+
818
+ if b == self.x:
819
+ y0[0] = y0[0] - lower
820
+ return HolonomicFunction(self.annihilator * D, self.x, x0, y0)
821
+
822
+ elif S(b).is_Number:
823
+ if indefinite_expr:
824
+ upper = indefinite_expr.subs(self.x, b)
825
+ if isinstance(upper, NaN):
826
+ upper = indefinite_expr.limit(self.x, b)
827
+ else:
828
+ upper = indefinite_integral.evalf(b)
829
+
830
+ return upper - lower
831
+
832
+
833
+ # if the upper limit is `x`, the answer will be a function
834
+ if b == self.x:
835
+ return HolonomicFunction(self.annihilator * D, self.x, a, y0)
836
+
837
+ # if the upper limits is a Number, a numerical value will be returned
838
+ elif S(b).is_Number:
839
+ try:
840
+ s = HolonomicFunction(self.annihilator * D, self.x, a,\
841
+ y0).to_expr()
842
+ indefinite = s.subs(self.x, b)
843
+ if not isinstance(indefinite, NaN):
844
+ return indefinite
845
+ else:
846
+ return s.limit(self.x, b)
847
+ except (NotHyperSeriesError, NotPowerSeriesError):
848
+ return HolonomicFunction(self.annihilator * D, self.x, a, y0).evalf(b)
849
+
850
+ return HolonomicFunction(self.annihilator * D, self.x)
851
+
852
+ def diff(self, *args, **kwargs):
853
+ r"""
854
+ Differentiation of the given Holonomic function.
855
+
856
+ Examples
857
+ ========
858
+
859
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
860
+ >>> from sympy import ZZ
861
+ >>> from sympy import symbols
862
+ >>> x = symbols('x')
863
+ >>> R, Dx = DifferentialOperators(ZZ.old_poly_ring(x),'Dx')
864
+ >>> HolonomicFunction(Dx**2 + 1, x, 0, [0, 1]).diff().to_expr()
865
+ cos(x)
866
+ >>> HolonomicFunction(Dx - 2, x, 0, [1]).diff().to_expr()
867
+ 2*exp(2*x)
868
+
869
+ See Also
870
+ ========
871
+
872
+ integrate
873
+ """
874
+ kwargs.setdefault('evaluate', True)
875
+ if args:
876
+ if args[0] != self.x:
877
+ return S.Zero
878
+ elif len(args) == 2:
879
+ sol = self
880
+ for i in range(args[1]):
881
+ sol = sol.diff(args[0])
882
+ return sol
883
+
884
+ ann = self.annihilator
885
+
886
+ # if the function is constant.
887
+ if ann.listofpoly[0] == ann.parent.base.zero and ann.order == 1:
888
+ return S.Zero
889
+
890
+ # if the coefficient of y in the differential equation is zero.
891
+ # a shifting is done to compute the answer in this case.
892
+ elif ann.listofpoly[0] == ann.parent.base.zero:
893
+
894
+ sol = DifferentialOperator(ann.listofpoly[1:], ann.parent)
895
+
896
+ if self._have_init_cond():
897
+ # if ordinary initial condition
898
+ if self.is_singularics() == False:
899
+ return HolonomicFunction(sol, self.x, self.x0, self.y0[1:])
900
+ # TODO: support for singular initial condition
901
+ return HolonomicFunction(sol, self.x)
902
+ else:
903
+ return HolonomicFunction(sol, self.x)
904
+
905
+ # the general algorithm
906
+ R = ann.parent.base
907
+ K = R.get_field()
908
+
909
+ seq_dmf = [K.new(i.rep) for i in ann.listofpoly]
910
+
911
+ # -y = a1*y'/a0 + a2*y''/a0 ... + an*y^n/a0
912
+ rhs = [i / seq_dmf[0] for i in seq_dmf[1:]]
913
+ rhs.insert(0, K.zero)
914
+
915
+ # differentiate both lhs and rhs
916
+ sol = _derivate_diff_eq(rhs)
917
+
918
+ # add the term y' in lhs to rhs
919
+ sol = _add_lists(sol, [K.zero, K.one])
920
+
921
+ sol = _normalize(sol[1:], self.annihilator.parent, negative=False)
922
+
923
+ if not self._have_init_cond() or self.is_singularics() == True:
924
+ return HolonomicFunction(sol, self.x)
925
+
926
+ y0 = _extend_y0(self, sol.order + 1)[1:]
927
+ return HolonomicFunction(sol, self.x, self.x0, y0)
928
+
929
+ def __eq__(self, other):
930
+ if self.annihilator == other.annihilator:
931
+ if self.x == other.x:
932
+ if self._have_init_cond() and other._have_init_cond():
933
+ if self.x0 == other.x0 and self.y0 == other.y0:
934
+ return True
935
+ else:
936
+ return False
937
+ else:
938
+ return True
939
+ else:
940
+ return False
941
+ else:
942
+ return False
943
+
944
+ def __mul__(self, other):
945
+ ann_self = self.annihilator
946
+
947
+ if not isinstance(other, HolonomicFunction):
948
+ other = sympify(other)
949
+
950
+ if other.has(self.x):
951
+ raise NotImplementedError(" Can't multiply a HolonomicFunction and expressions/functions.")
952
+
953
+ if not self._have_init_cond():
954
+ return self
955
+ else:
956
+ y0 = _extend_y0(self, ann_self.order)
957
+ y1 = []
958
+
959
+ for j in y0:
960
+ y1.append((Poly.new(j, self.x) * other).rep)
961
+
962
+ return HolonomicFunction(ann_self, self.x, self.x0, y1)
963
+
964
+ if self.annihilator.parent.base != other.annihilator.parent.base:
965
+ a, b = self.unify(other)
966
+ return a * b
967
+
968
+ ann_other = other.annihilator
969
+
970
+ list_self = []
971
+ list_other = []
972
+
973
+ a = ann_self.order
974
+ b = ann_other.order
975
+
976
+ R = ann_self.parent.base
977
+ K = R.get_field()
978
+
979
+ for j in ann_self.listofpoly:
980
+ list_self.append(K.new(j.rep))
981
+
982
+ for j in ann_other.listofpoly:
983
+ list_other.append(K.new(j.rep))
984
+
985
+ # will be used to reduce the degree
986
+ self_red = [-list_self[i] / list_self[a] for i in range(a)]
987
+
988
+ other_red = [-list_other[i] / list_other[b] for i in range(b)]
989
+
990
+ # coeff_mull[i][j] is the coefficient of Dx^i(f).Dx^j(g)
991
+ coeff_mul = [[K.zero for i in range(b + 1)] for j in range(a + 1)]
992
+ coeff_mul[0][0] = K.one
993
+
994
+ # making the ansatz
995
+ lin_sys_elements = [[coeff_mul[i][j] for i in range(a) for j in range(b)]]
996
+ lin_sys = DomainMatrix(lin_sys_elements, (1, a*b), K).transpose()
997
+
998
+ homo_sys = DomainMatrix.zeros((a*b, 1), K)
999
+
1000
+ sol = _find_nonzero_solution(lin_sys, homo_sys)
1001
+
1002
+ # until a non trivial solution is found
1003
+ while sol.is_zero_matrix:
1004
+
1005
+ # updating the coefficients Dx^i(f).Dx^j(g) for next degree
1006
+ for i in range(a - 1, -1, -1):
1007
+ for j in range(b - 1, -1, -1):
1008
+ coeff_mul[i][j + 1] += coeff_mul[i][j]
1009
+ coeff_mul[i + 1][j] += coeff_mul[i][j]
1010
+ if isinstance(coeff_mul[i][j], K.dtype):
1011
+ coeff_mul[i][j] = DMFdiff(coeff_mul[i][j])
1012
+ else:
1013
+ coeff_mul[i][j] = coeff_mul[i][j].diff(self.x)
1014
+
1015
+ # reduce the terms to lower power using annihilators of f, g
1016
+ for i in range(a + 1):
1017
+ if not coeff_mul[i][b].is_zero:
1018
+ for j in range(b):
1019
+ coeff_mul[i][j] += other_red[j] * \
1020
+ coeff_mul[i][b]
1021
+ coeff_mul[i][b] = K.zero
1022
+
1023
+ # not d2 + 1, as that is already covered in previous loop
1024
+ for j in range(b):
1025
+ if not coeff_mul[a][j] == 0:
1026
+ for i in range(a):
1027
+ coeff_mul[i][j] += self_red[i] * \
1028
+ coeff_mul[a][j]
1029
+ coeff_mul[a][j] = K.zero
1030
+
1031
+ lin_sys_elements.append([coeff_mul[i][j] for i in range(a) for j in range(b)])
1032
+ lin_sys = DomainMatrix(lin_sys_elements, (len(lin_sys_elements), a*b), K).transpose()
1033
+
1034
+ sol = _find_nonzero_solution(lin_sys, homo_sys)
1035
+
1036
+ sol_ann = _normalize(sol.flat(), self.annihilator.parent, negative=False)
1037
+
1038
+ if not (self._have_init_cond() and other._have_init_cond()):
1039
+ return HolonomicFunction(sol_ann, self.x)
1040
+
1041
+ if self.is_singularics() == False and other.is_singularics() == False:
1042
+
1043
+ # if both the conditions are at same point
1044
+ if self.x0 == other.x0:
1045
+
1046
+ # try to find more initial conditions
1047
+ y0_self = _extend_y0(self, sol_ann.order)
1048
+ y0_other = _extend_y0(other, sol_ann.order)
1049
+ # h(x0) = f(x0) * g(x0)
1050
+ y0 = [y0_self[0] * y0_other[0]]
1051
+
1052
+ # coefficient of Dx^j(f)*Dx^i(g) in Dx^i(fg)
1053
+ for i in range(1, min(len(y0_self), len(y0_other))):
1054
+ coeff = [[0 for i in range(i + 1)] for j in range(i + 1)]
1055
+ for j in range(i + 1):
1056
+ for k in range(i + 1):
1057
+ if j + k == i:
1058
+ coeff[j][k] = binomial(i, j)
1059
+
1060
+ sol = 0
1061
+ for j in range(i + 1):
1062
+ for k in range(i + 1):
1063
+ sol += coeff[j][k]* y0_self[j] * y0_other[k]
1064
+
1065
+ y0.append(sol)
1066
+
1067
+ return HolonomicFunction(sol_ann, self.x, self.x0, y0)
1068
+
1069
+ # if the points are different, consider one
1070
+ else:
1071
+
1072
+ selfat0 = self.annihilator.is_singular(0)
1073
+ otherat0 = other.annihilator.is_singular(0)
1074
+
1075
+ if self.x0 == 0 and not selfat0 and not otherat0:
1076
+ return self * other.change_ics(0)
1077
+
1078
+ elif other.x0 == 0 and not selfat0 and not otherat0:
1079
+ return self.change_ics(0) * other
1080
+
1081
+ else:
1082
+ selfatx0 = self.annihilator.is_singular(self.x0)
1083
+ otheratx0 = other.annihilator.is_singular(self.x0)
1084
+
1085
+ if not selfatx0 and not otheratx0:
1086
+ return self * other.change_ics(self.x0)
1087
+
1088
+ else:
1089
+ return self.change_ics(other.x0) * other
1090
+
1091
+ if self.x0 != other.x0:
1092
+ return HolonomicFunction(sol_ann, self.x)
1093
+
1094
+ # if the functions have singular_ics
1095
+ y1 = None
1096
+ y2 = None
1097
+
1098
+ if self.is_singularics() == False and other.is_singularics() == True:
1099
+ _y0 = [j / factorial(i) for i, j in enumerate(self.y0)]
1100
+ y1 = {S.Zero: _y0}
1101
+ y2 = other.y0
1102
+ elif self.is_singularics() == True and other.is_singularics() == False:
1103
+ _y0 = [j / factorial(i) for i, j in enumerate(other.y0)]
1104
+ y1 = self.y0
1105
+ y2 = {S.Zero: _y0}
1106
+ elif self.is_singularics() == True and other.is_singularics() == True:
1107
+ y1 = self.y0
1108
+ y2 = other.y0
1109
+
1110
+ y0 = {}
1111
+ # multiply every possible pair of the series terms
1112
+ for i in y1:
1113
+ for j in y2:
1114
+ k = min(len(y1[i]), len(y2[j]))
1115
+ c = []
1116
+ for a in range(k):
1117
+ s = S.Zero
1118
+ for b in range(a + 1):
1119
+ s += y1[i][b] * y2[j][a - b]
1120
+ c.append(s)
1121
+ if not i + j in y0:
1122
+ y0[i + j] = c
1123
+ else:
1124
+ y0[i + j] = [a + b for a, b in zip(c, y0[i + j])]
1125
+ return HolonomicFunction(sol_ann, self.x, self.x0, y0)
1126
+
1127
+ __rmul__ = __mul__
1128
+
1129
+ def __sub__(self, other):
1130
+ return self + other * -1
1131
+
1132
+ def __rsub__(self, other):
1133
+ return self * -1 + other
1134
+
1135
+ def __neg__(self):
1136
+ return -1 * self
1137
+
1138
+ def __truediv__(self, other):
1139
+ return self * (S.One / other)
1140
+
1141
+ def __pow__(self, n):
1142
+ if self.annihilator.order <= 1:
1143
+ ann = self.annihilator
1144
+ parent = ann.parent
1145
+
1146
+ if self.y0 is None:
1147
+ y0 = None
1148
+ else:
1149
+ y0 = [list(self.y0)[0] ** n]
1150
+
1151
+ p0 = ann.listofpoly[0]
1152
+ p1 = ann.listofpoly[1]
1153
+
1154
+ p0 = (Poly.new(p0, self.x) * n).rep
1155
+
1156
+ sol = [parent.base.to_sympy(i) for i in [p0, p1]]
1157
+ dd = DifferentialOperator(sol, parent)
1158
+ return HolonomicFunction(dd, self.x, self.x0, y0)
1159
+ if n < 0:
1160
+ raise NotHolonomicError("Negative Power on a Holonomic Function")
1161
+ if n == 0:
1162
+ Dx = self.annihilator.parent.derivative_operator
1163
+ return HolonomicFunction(Dx, self.x, S.Zero, [S.One])
1164
+ if n == 1:
1165
+ return self
1166
+ else:
1167
+ if n % 2 == 1:
1168
+ powreduce = self**(n - 1)
1169
+ return powreduce * self
1170
+ elif n % 2 == 0:
1171
+ powreduce = self**(n / 2)
1172
+ return powreduce * powreduce
1173
+
1174
+ def degree(self):
1175
+ """
1176
+ Returns the highest power of `x` in the annihilator.
1177
+ """
1178
+ sol = [i.degree() for i in self.annihilator.listofpoly]
1179
+ return max(sol)
1180
+
1181
+ def composition(self, expr, *args, **kwargs):
1182
+ """
1183
+ Returns function after composition of a holonomic
1184
+ function with an algebraic function. The method cannot compute
1185
+ initial conditions for the result by itself, so they can be also be
1186
+ provided.
1187
+
1188
+ Examples
1189
+ ========
1190
+
1191
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
1192
+ >>> from sympy import QQ
1193
+ >>> from sympy import symbols
1194
+ >>> x = symbols('x')
1195
+ >>> R, Dx = DifferentialOperators(QQ.old_poly_ring(x),'Dx')
1196
+ >>> HolonomicFunction(Dx - 1, x).composition(x**2, 0, [1]) # e^(x**2)
1197
+ HolonomicFunction((-2*x) + (1)*Dx, x, 0, [1])
1198
+ >>> HolonomicFunction(Dx**2 + 1, x).composition(x**2 - 1, 1, [1, 0])
1199
+ HolonomicFunction((4*x**3) + (-1)*Dx + (x)*Dx**2, x, 1, [1, 0])
1200
+
1201
+ See Also
1202
+ ========
1203
+
1204
+ from_hyper
1205
+ """
1206
+
1207
+ R = self.annihilator.parent
1208
+ a = self.annihilator.order
1209
+ diff = expr.diff(self.x)
1210
+ listofpoly = self.annihilator.listofpoly
1211
+
1212
+ for i, j in enumerate(listofpoly):
1213
+ if isinstance(j, self.annihilator.parent.base.dtype):
1214
+ listofpoly[i] = self.annihilator.parent.base.to_sympy(j)
1215
+
1216
+ r = listofpoly[a].subs({self.x:expr})
1217
+ subs = [-listofpoly[i].subs({self.x:expr}) / r for i in range (a)]
1218
+ coeffs = [S.Zero for i in range(a)] # coeffs[i] == coeff of (D^i f)(a) in D^k (f(a))
1219
+ coeffs[0] = S.One
1220
+ system = [coeffs]
1221
+ homogeneous = Matrix([[S.Zero for i in range(a)]]).transpose()
1222
+ while True:
1223
+ coeffs_next = [p.diff(self.x) for p in coeffs]
1224
+ for i in range(a - 1):
1225
+ coeffs_next[i + 1] += (coeffs[i] * diff)
1226
+ for i in range(a):
1227
+ coeffs_next[i] += (coeffs[-1] * subs[i] * diff)
1228
+ coeffs = coeffs_next
1229
+ # check for linear relations
1230
+ system.append(coeffs)
1231
+ sol, taus = (Matrix(system).transpose()
1232
+ ).gauss_jordan_solve(homogeneous)
1233
+ if sol.is_zero_matrix is not True:
1234
+ break
1235
+
1236
+ tau = list(taus)[0]
1237
+ sol = sol.subs(tau, 1)
1238
+ sol = _normalize(sol[0:], R, negative=False)
1239
+
1240
+ # if initial conditions are given for the resulting function
1241
+ if args:
1242
+ return HolonomicFunction(sol, self.x, args[0], args[1])
1243
+ return HolonomicFunction(sol, self.x)
1244
+
1245
+ def to_sequence(self, lb=True):
1246
+ r"""
1247
+ Finds recurrence relation for the coefficients in the series expansion
1248
+ of the function about :math:`x_0`, where :math:`x_0` is the point at
1249
+ which the initial condition is stored.
1250
+
1251
+ Explanation
1252
+ ===========
1253
+
1254
+ If the point :math:`x_0` is ordinary, solution of the form :math:`[(R, n_0)]`
1255
+ is returned. Where :math:`R` is the recurrence relation and :math:`n_0` is the
1256
+ smallest ``n`` for which the recurrence holds true.
1257
+
1258
+ If the point :math:`x_0` is regular singular, a list of solutions in
1259
+ the format :math:`(R, p, n_0)` is returned, i.e. `[(R, p, n_0), ... ]`.
1260
+ Each tuple in this vector represents a recurrence relation :math:`R`
1261
+ associated with a root of the indicial equation ``p``. Conditions of
1262
+ a different format can also be provided in this case, see the
1263
+ docstring of HolonomicFunction class.
1264
+
1265
+ If it's not possible to numerically compute a initial condition,
1266
+ it is returned as a symbol :math:`C_j`, denoting the coefficient of
1267
+ :math:`(x - x_0)^j` in the power series about :math:`x_0`.
1268
+
1269
+ Examples
1270
+ ========
1271
+
1272
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
1273
+ >>> from sympy import QQ
1274
+ >>> from sympy import symbols, S
1275
+ >>> x = symbols('x')
1276
+ >>> R, Dx = DifferentialOperators(QQ.old_poly_ring(x),'Dx')
1277
+ >>> HolonomicFunction(Dx - 1, x, 0, [1]).to_sequence()
1278
+ [(HolonomicSequence((-1) + (n + 1)Sn, n), u(0) = 1, 0)]
1279
+ >>> HolonomicFunction((1 + x)*Dx**2 + Dx, x, 0, [0, 1]).to_sequence()
1280
+ [(HolonomicSequence((n**2) + (n**2 + n)Sn, n), u(0) = 0, u(1) = 1, u(2) = -1/2, 2)]
1281
+ >>> HolonomicFunction(-S(1)/2 + x*Dx, x, 0, {S(1)/2: [1]}).to_sequence()
1282
+ [(HolonomicSequence((n), n), u(0) = 1, 1/2, 1)]
1283
+
1284
+ See Also
1285
+ ========
1286
+
1287
+ HolonomicFunction.series
1288
+
1289
+ References
1290
+ ==========
1291
+
1292
+ .. [1] https://hal.inria.fr/inria-00070025/document
1293
+ .. [2] https://www3.risc.jku.at/publications/download/risc_2244/DIPLFORM.pdf
1294
+
1295
+ """
1296
+
1297
+ if self.x0 != 0:
1298
+ return self.shift_x(self.x0).to_sequence()
1299
+
1300
+ # check whether a power series exists if the point is singular
1301
+ if self.annihilator.is_singular(self.x0):
1302
+ return self._frobenius(lb=lb)
1303
+
1304
+ dict1 = {}
1305
+ n = Symbol('n', integer=True)
1306
+ dom = self.annihilator.parent.base.dom
1307
+ R, _ = RecurrenceOperators(dom.old_poly_ring(n), 'Sn')
1308
+
1309
+ # substituting each term of the form `x^k Dx^j` in the
1310
+ # annihilator, according to the formula below:
1311
+ # x^k Dx^j = Sum(rf(n + 1 - k, j) * a(n + j - k) * x^n, (n, k, oo))
1312
+ # for explanation see [2].
1313
+ for i, j in enumerate(self.annihilator.listofpoly):
1314
+
1315
+ listofdmp = j.all_coeffs()
1316
+ degree = len(listofdmp) - 1
1317
+
1318
+ for k in range(degree + 1):
1319
+ coeff = listofdmp[degree - k]
1320
+
1321
+ if coeff == 0:
1322
+ continue
1323
+
1324
+ if (i - k, k) in dict1:
1325
+ dict1[(i - k, k)] += (dom.to_sympy(coeff) * rf(n - k + 1, i))
1326
+ else:
1327
+ dict1[(i - k, k)] = (dom.to_sympy(coeff) * rf(n - k + 1, i))
1328
+
1329
+
1330
+ sol = []
1331
+ keylist = [i[0] for i in dict1]
1332
+ lower = min(keylist)
1333
+ upper = max(keylist)
1334
+ degree = self.degree()
1335
+
1336
+ # the recurrence relation holds for all values of
1337
+ # n greater than smallest_n, i.e. n >= smallest_n
1338
+ smallest_n = lower + degree
1339
+ dummys = {}
1340
+ eqs = []
1341
+ unknowns = []
1342
+
1343
+ # an appropriate shift of the recurrence
1344
+ for j in range(lower, upper + 1):
1345
+ if j in keylist:
1346
+ temp = S.Zero
1347
+ for k in dict1.keys():
1348
+ if k[0] == j:
1349
+ temp += dict1[k].subs(n, n - lower)
1350
+ sol.append(temp)
1351
+ else:
1352
+ sol.append(S.Zero)
1353
+
1354
+ # the recurrence relation
1355
+ sol = RecurrenceOperator(sol, R)
1356
+
1357
+ # computing the initial conditions for recurrence
1358
+ order = sol.order
1359
+ all_roots = roots(R.base.to_sympy(sol.listofpoly[-1]), n, filter='Z')
1360
+ all_roots = all_roots.keys()
1361
+
1362
+ if all_roots:
1363
+ max_root = max(all_roots) + 1
1364
+ smallest_n = max(max_root, smallest_n)
1365
+ order += smallest_n
1366
+
1367
+ y0 = _extend_y0(self, order)
1368
+ u0 = []
1369
+
1370
+ # u(n) = y^n(0)/factorial(n)
1371
+ for i, j in enumerate(y0):
1372
+ u0.append(j / factorial(i))
1373
+
1374
+ # if sufficient conditions can't be computed then
1375
+ # try to use the series method i.e.
1376
+ # equate the coefficients of x^k in the equation formed by
1377
+ # substituting the series in differential equation, to zero.
1378
+ if len(u0) < order:
1379
+
1380
+ for i in range(degree):
1381
+ eq = S.Zero
1382
+
1383
+ for j in dict1:
1384
+
1385
+ if i + j[0] < 0:
1386
+ dummys[i + j[0]] = S.Zero
1387
+
1388
+ elif i + j[0] < len(u0):
1389
+ dummys[i + j[0]] = u0[i + j[0]]
1390
+
1391
+ elif not i + j[0] in dummys:
1392
+ dummys[i + j[0]] = Symbol('C_%s' %(i + j[0]))
1393
+ unknowns.append(dummys[i + j[0]])
1394
+
1395
+ if j[1] <= i:
1396
+ eq += dict1[j].subs(n, i) * dummys[i + j[0]]
1397
+
1398
+ eqs.append(eq)
1399
+
1400
+ # solve the system of equations formed
1401
+ soleqs = solve(eqs, *unknowns)
1402
+
1403
+ if isinstance(soleqs, dict):
1404
+
1405
+ for i in range(len(u0), order):
1406
+
1407
+ if i not in dummys:
1408
+ dummys[i] = Symbol('C_%s' %i)
1409
+
1410
+ if dummys[i] in soleqs:
1411
+ u0.append(soleqs[dummys[i]])
1412
+
1413
+ else:
1414
+ u0.append(dummys[i])
1415
+
1416
+ if lb:
1417
+ return [(HolonomicSequence(sol, u0), smallest_n)]
1418
+ return [HolonomicSequence(sol, u0)]
1419
+
1420
+ for i in range(len(u0), order):
1421
+
1422
+ if i not in dummys:
1423
+ dummys[i] = Symbol('C_%s' %i)
1424
+
1425
+ s = False
1426
+ for j in soleqs:
1427
+ if dummys[i] in j:
1428
+ u0.append(j[dummys[i]])
1429
+ s = True
1430
+ if not s:
1431
+ u0.append(dummys[i])
1432
+
1433
+ if lb:
1434
+ return [(HolonomicSequence(sol, u0), smallest_n)]
1435
+
1436
+ return [HolonomicSequence(sol, u0)]
1437
+
1438
+ def _frobenius(self, lb=True):
1439
+ # compute the roots of indicial equation
1440
+ indicialroots = self._indicial()
1441
+
1442
+ reals = []
1443
+ compl = []
1444
+ for i in ordered(indicialroots.keys()):
1445
+ if i.is_real:
1446
+ reals.extend([i] * indicialroots[i])
1447
+ else:
1448
+ a, b = i.as_real_imag()
1449
+ compl.extend([(i, a, b)] * indicialroots[i])
1450
+
1451
+ # sort the roots for a fixed ordering of solution
1452
+ compl.sort(key=lambda x : x[1])
1453
+ compl.sort(key=lambda x : x[2])
1454
+ reals.sort()
1455
+
1456
+ # grouping the roots, roots differ by an integer are put in the same group.
1457
+ grp = []
1458
+
1459
+ for i in reals:
1460
+ intdiff = False
1461
+ if len(grp) == 0:
1462
+ grp.append([i])
1463
+ continue
1464
+ for j in grp:
1465
+ if int(j[0] - i) == j[0] - i:
1466
+ j.append(i)
1467
+ intdiff = True
1468
+ break
1469
+ if not intdiff:
1470
+ grp.append([i])
1471
+
1472
+ # True if none of the roots differ by an integer i.e.
1473
+ # each element in group have only one member
1474
+ independent = True if all(len(i) == 1 for i in grp) else False
1475
+
1476
+ allpos = all(i >= 0 for i in reals)
1477
+ allint = all(int(i) == i for i in reals)
1478
+
1479
+ # if initial conditions are provided
1480
+ # then use them.
1481
+ if self.is_singularics() == True:
1482
+ rootstoconsider = []
1483
+ for i in ordered(self.y0.keys()):
1484
+ for j in ordered(indicialroots.keys()):
1485
+ if equal_valued(j, i):
1486
+ rootstoconsider.append(i)
1487
+
1488
+ elif allpos and allint:
1489
+ rootstoconsider = [min(reals)]
1490
+
1491
+ elif independent:
1492
+ rootstoconsider = [i[0] for i in grp] + [j[0] for j in compl]
1493
+
1494
+ elif not allint:
1495
+ rootstoconsider = []
1496
+ for i in reals:
1497
+ if not int(i) == i:
1498
+ rootstoconsider.append(i)
1499
+
1500
+ elif not allpos:
1501
+
1502
+ if not self._have_init_cond() or S(self.y0[0]).is_finite == False:
1503
+ rootstoconsider = [min(reals)]
1504
+
1505
+ else:
1506
+ posroots = []
1507
+ for i in reals:
1508
+ if i >= 0:
1509
+ posroots.append(i)
1510
+ rootstoconsider = [min(posroots)]
1511
+
1512
+ n = Symbol('n', integer=True)
1513
+ dom = self.annihilator.parent.base.dom
1514
+ R, _ = RecurrenceOperators(dom.old_poly_ring(n), 'Sn')
1515
+
1516
+ finalsol = []
1517
+ char = ord('C')
1518
+
1519
+ for p in rootstoconsider:
1520
+ dict1 = {}
1521
+
1522
+ for i, j in enumerate(self.annihilator.listofpoly):
1523
+
1524
+ listofdmp = j.all_coeffs()
1525
+ degree = len(listofdmp) - 1
1526
+
1527
+ for k in range(degree + 1):
1528
+ coeff = listofdmp[degree - k]
1529
+
1530
+ if coeff == 0:
1531
+ continue
1532
+
1533
+ if (i - k, k - i) in dict1:
1534
+ dict1[(i - k, k - i)] += (dom.to_sympy(coeff) * rf(n - k + 1 + p, i))
1535
+ else:
1536
+ dict1[(i - k, k - i)] = (dom.to_sympy(coeff) * rf(n - k + 1 + p, i))
1537
+
1538
+ sol = []
1539
+ keylist = [i[0] for i in dict1]
1540
+ lower = min(keylist)
1541
+ upper = max(keylist)
1542
+ degree = max([i[1] for i in dict1])
1543
+ degree2 = min([i[1] for i in dict1])
1544
+
1545
+ smallest_n = lower + degree
1546
+ dummys = {}
1547
+ eqs = []
1548
+ unknowns = []
1549
+
1550
+ for j in range(lower, upper + 1):
1551
+ if j in keylist:
1552
+ temp = S.Zero
1553
+ for k in dict1.keys():
1554
+ if k[0] == j:
1555
+ temp += dict1[k].subs(n, n - lower)
1556
+ sol.append(temp)
1557
+ else:
1558
+ sol.append(S.Zero)
1559
+
1560
+ # the recurrence relation
1561
+ sol = RecurrenceOperator(sol, R)
1562
+
1563
+ # computing the initial conditions for recurrence
1564
+ order = sol.order
1565
+ all_roots = roots(R.base.to_sympy(sol.listofpoly[-1]), n, filter='Z')
1566
+ all_roots = all_roots.keys()
1567
+
1568
+ if all_roots:
1569
+ max_root = max(all_roots) + 1
1570
+ smallest_n = max(max_root, smallest_n)
1571
+ order += smallest_n
1572
+
1573
+ u0 = []
1574
+
1575
+ if self.is_singularics() == True:
1576
+ u0 = self.y0[p]
1577
+
1578
+ elif self.is_singularics() == False and p >= 0 and int(p) == p and len(rootstoconsider) == 1:
1579
+ y0 = _extend_y0(self, order + int(p))
1580
+ # u(n) = y^n(0)/factorial(n)
1581
+ if len(y0) > int(p):
1582
+ for i in range(int(p), len(y0)):
1583
+ u0.append(y0[i] / factorial(i))
1584
+
1585
+ if len(u0) < order:
1586
+
1587
+ for i in range(degree2, degree):
1588
+ eq = S.Zero
1589
+
1590
+ for j in dict1:
1591
+ if i + j[0] < 0:
1592
+ dummys[i + j[0]] = S.Zero
1593
+
1594
+ elif i + j[0] < len(u0):
1595
+ dummys[i + j[0]] = u0[i + j[0]]
1596
+
1597
+ elif not i + j[0] in dummys:
1598
+ letter = chr(char) + '_%s' %(i + j[0])
1599
+ dummys[i + j[0]] = Symbol(letter)
1600
+ unknowns.append(dummys[i + j[0]])
1601
+
1602
+ if j[1] <= i:
1603
+ eq += dict1[j].subs(n, i) * dummys[i + j[0]]
1604
+
1605
+ eqs.append(eq)
1606
+
1607
+ # solve the system of equations formed
1608
+ soleqs = solve(eqs, *unknowns)
1609
+
1610
+ if isinstance(soleqs, dict):
1611
+
1612
+ for i in range(len(u0), order):
1613
+
1614
+ if i not in dummys:
1615
+ letter = chr(char) + '_%s' %i
1616
+ dummys[i] = Symbol(letter)
1617
+
1618
+ if dummys[i] in soleqs:
1619
+ u0.append(soleqs[dummys[i]])
1620
+
1621
+ else:
1622
+ u0.append(dummys[i])
1623
+
1624
+ if lb:
1625
+ finalsol.append((HolonomicSequence(sol, u0), p, smallest_n))
1626
+ continue
1627
+ else:
1628
+ finalsol.append((HolonomicSequence(sol, u0), p))
1629
+ continue
1630
+
1631
+ for i in range(len(u0), order):
1632
+
1633
+ if i not in dummys:
1634
+ letter = chr(char) + '_%s' %i
1635
+ dummys[i] = Symbol(letter)
1636
+
1637
+ s = False
1638
+ for j in soleqs:
1639
+ if dummys[i] in j:
1640
+ u0.append(j[dummys[i]])
1641
+ s = True
1642
+ if not s:
1643
+ u0.append(dummys[i])
1644
+ if lb:
1645
+ finalsol.append((HolonomicSequence(sol, u0), p, smallest_n))
1646
+
1647
+ else:
1648
+ finalsol.append((HolonomicSequence(sol, u0), p))
1649
+ char += 1
1650
+ return finalsol
1651
+
1652
+ def series(self, n=6, coefficient=False, order=True, _recur=None):
1653
+ r"""
1654
+ Finds the power series expansion of given holonomic function about :math:`x_0`.
1655
+
1656
+ Explanation
1657
+ ===========
1658
+
1659
+ A list of series might be returned if :math:`x_0` is a regular point with
1660
+ multiple roots of the indicial equation.
1661
+
1662
+ Examples
1663
+ ========
1664
+
1665
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
1666
+ >>> from sympy import QQ
1667
+ >>> from sympy import symbols
1668
+ >>> x = symbols('x')
1669
+ >>> R, Dx = DifferentialOperators(QQ.old_poly_ring(x),'Dx')
1670
+ >>> HolonomicFunction(Dx - 1, x, 0, [1]).series() # e^x
1671
+ 1 + x + x**2/2 + x**3/6 + x**4/24 + x**5/120 + O(x**6)
1672
+ >>> HolonomicFunction(Dx**2 + 1, x, 0, [0, 1]).series(n=8) # sin(x)
1673
+ x - x**3/6 + x**5/120 - x**7/5040 + O(x**8)
1674
+
1675
+ See Also
1676
+ ========
1677
+
1678
+ HolonomicFunction.to_sequence
1679
+ """
1680
+
1681
+ if _recur is None:
1682
+ recurrence = self.to_sequence()
1683
+ else:
1684
+ recurrence = _recur
1685
+
1686
+ if isinstance(recurrence, tuple) and len(recurrence) == 2:
1687
+ recurrence = recurrence[0]
1688
+ constantpower = 0
1689
+ elif isinstance(recurrence, tuple) and len(recurrence) == 3:
1690
+ constantpower = recurrence[1]
1691
+ recurrence = recurrence[0]
1692
+
1693
+ elif len(recurrence) == 1 and len(recurrence[0]) == 2:
1694
+ recurrence = recurrence[0][0]
1695
+ constantpower = 0
1696
+ elif len(recurrence) == 1 and len(recurrence[0]) == 3:
1697
+ constantpower = recurrence[0][1]
1698
+ recurrence = recurrence[0][0]
1699
+ else:
1700
+ sol = []
1701
+ for i in recurrence:
1702
+ sol.append(self.series(_recur=i))
1703
+ return sol
1704
+
1705
+ n = n - int(constantpower)
1706
+ l = len(recurrence.u0) - 1
1707
+ k = recurrence.recurrence.order
1708
+ x = self.x
1709
+ x0 = self.x0
1710
+ seq_dmp = recurrence.recurrence.listofpoly
1711
+ R = recurrence.recurrence.parent.base
1712
+ K = R.get_field()
1713
+ seq = []
1714
+
1715
+ for i, j in enumerate(seq_dmp):
1716
+ seq.append(K.new(j.rep))
1717
+
1718
+ sub = [-seq[i] / seq[k] for i in range(k)]
1719
+ sol = list(recurrence.u0)
1720
+
1721
+ if l + 1 >= n:
1722
+ pass
1723
+ else:
1724
+ # use the initial conditions to find the next term
1725
+ for i in range(l + 1 - k, n - k):
1726
+ coeff = S.Zero
1727
+ for j in range(k):
1728
+ if i + j >= 0:
1729
+ coeff += DMFsubs(sub[j], i) * sol[i + j]
1730
+ sol.append(coeff)
1731
+
1732
+ if coefficient:
1733
+ return sol
1734
+
1735
+ ser = S.Zero
1736
+ for i, j in enumerate(sol):
1737
+ ser += x**(i + constantpower) * j
1738
+ if order:
1739
+ ser += Order(x**(n + int(constantpower)), x)
1740
+ if x0 != 0:
1741
+ return ser.subs(x, x - x0)
1742
+ return ser
1743
+
1744
+ def _indicial(self):
1745
+ """
1746
+ Computes roots of the Indicial equation.
1747
+ """
1748
+
1749
+ if self.x0 != 0:
1750
+ return self.shift_x(self.x0)._indicial()
1751
+
1752
+ list_coeff = self.annihilator.listofpoly
1753
+ R = self.annihilator.parent.base
1754
+ x = self.x
1755
+ s = R.zero
1756
+ y = R.one
1757
+
1758
+ def _pole_degree(poly):
1759
+ root_all = roots(R.to_sympy(poly), x, filter='Z')
1760
+ if 0 in root_all.keys():
1761
+ return root_all[0]
1762
+ else:
1763
+ return 0
1764
+
1765
+ degree = [j.degree() for j in list_coeff]
1766
+ degree = max(degree)
1767
+ inf = 10 * (max(1, degree) + max(1, self.annihilator.order))
1768
+
1769
+ deg = lambda q: inf if q.is_zero else _pole_degree(q)
1770
+ b = deg(list_coeff[0])
1771
+
1772
+ for j in range(1, len(list_coeff)):
1773
+ b = min(b, deg(list_coeff[j]) - j)
1774
+
1775
+ for i, j in enumerate(list_coeff):
1776
+ listofdmp = j.all_coeffs()
1777
+ degree = len(listofdmp) - 1
1778
+ if - i - b <= 0 and degree - i - b >= 0:
1779
+ s = s + listofdmp[degree - i - b] * y
1780
+ y *= x - i
1781
+
1782
+ return roots(R.to_sympy(s), x)
1783
+
1784
+ def evalf(self, points, method='RK4', h=0.05, derivatives=False):
1785
+ r"""
1786
+ Finds numerical value of a holonomic function using numerical methods.
1787
+ (RK4 by default). A set of points (real or complex) must be provided
1788
+ which will be the path for the numerical integration.
1789
+
1790
+ Explanation
1791
+ ===========
1792
+
1793
+ The path should be given as a list :math:`[x_1, x_2, \dots x_n]`. The numerical
1794
+ values will be computed at each point in this order
1795
+ :math:`x_1 \rightarrow x_2 \rightarrow x_3 \dots \rightarrow x_n`.
1796
+
1797
+ Returns values of the function at :math:`x_1, x_2, \dots x_n` in a list.
1798
+
1799
+ Examples
1800
+ ========
1801
+
1802
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
1803
+ >>> from sympy import QQ
1804
+ >>> from sympy import symbols
1805
+ >>> x = symbols('x')
1806
+ >>> R, Dx = DifferentialOperators(QQ.old_poly_ring(x),'Dx')
1807
+
1808
+ A straight line on the real axis from (0 to 1)
1809
+
1810
+ >>> r = [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1]
1811
+
1812
+ Runge-Kutta 4th order on e^x from 0.1 to 1.
1813
+ Exact solution at 1 is 2.71828182845905
1814
+
1815
+ >>> HolonomicFunction(Dx - 1, x, 0, [1]).evalf(r)
1816
+ [1.10517083333333, 1.22140257085069, 1.34985849706254, 1.49182424008069,
1817
+ 1.64872063859684, 1.82211796209193, 2.01375162659678, 2.22553956329232,
1818
+ 2.45960141378007, 2.71827974413517]
1819
+
1820
+ Euler's method for the same
1821
+
1822
+ >>> HolonomicFunction(Dx - 1, x, 0, [1]).evalf(r, method='Euler')
1823
+ [1.1, 1.21, 1.331, 1.4641, 1.61051, 1.771561, 1.9487171, 2.14358881,
1824
+ 2.357947691, 2.5937424601]
1825
+
1826
+ One can also observe that the value obtained using Runge-Kutta 4th order
1827
+ is much more accurate than Euler's method.
1828
+ """
1829
+
1830
+ from sympy.holonomic.numerical import _evalf
1831
+ lp = False
1832
+
1833
+ # if a point `b` is given instead of a mesh
1834
+ if not hasattr(points, "__iter__"):
1835
+ lp = True
1836
+ b = S(points)
1837
+ if self.x0 == b:
1838
+ return _evalf(self, [b], method=method, derivatives=derivatives)[-1]
1839
+
1840
+ if not b.is_Number:
1841
+ raise NotImplementedError
1842
+
1843
+ a = self.x0
1844
+ if a > b:
1845
+ h = -h
1846
+ n = int((b - a) / h)
1847
+ points = [a + h]
1848
+ for i in range(n - 1):
1849
+ points.append(points[-1] + h)
1850
+
1851
+ for i in roots(self.annihilator.parent.base.to_sympy(self.annihilator.listofpoly[-1]), self.x):
1852
+ if i == self.x0 or i in points:
1853
+ raise SingularityError(self, i)
1854
+
1855
+ if lp:
1856
+ return _evalf(self, points, method=method, derivatives=derivatives)[-1]
1857
+ return _evalf(self, points, method=method, derivatives=derivatives)
1858
+
1859
+ def change_x(self, z):
1860
+ """
1861
+ Changes only the variable of Holonomic Function, for internal
1862
+ purposes. For composition use HolonomicFunction.composition()
1863
+ """
1864
+
1865
+ dom = self.annihilator.parent.base.dom
1866
+ R = dom.old_poly_ring(z)
1867
+ parent, _ = DifferentialOperators(R, 'Dx')
1868
+ sol = []
1869
+ for j in self.annihilator.listofpoly:
1870
+ sol.append(R(j.rep))
1871
+ sol = DifferentialOperator(sol, parent)
1872
+ return HolonomicFunction(sol, z, self.x0, self.y0)
1873
+
1874
+ def shift_x(self, a):
1875
+ """
1876
+ Substitute `x + a` for `x`.
1877
+ """
1878
+
1879
+ x = self.x
1880
+ listaftershift = self.annihilator.listofpoly
1881
+ base = self.annihilator.parent.base
1882
+
1883
+ sol = [base.from_sympy(base.to_sympy(i).subs(x, x + a)) for i in listaftershift]
1884
+ sol = DifferentialOperator(sol, self.annihilator.parent)
1885
+ x0 = self.x0 - a
1886
+ if not self._have_init_cond():
1887
+ return HolonomicFunction(sol, x)
1888
+ return HolonomicFunction(sol, x, x0, self.y0)
1889
+
1890
+ def to_hyper(self, as_list=False, _recur=None):
1891
+ r"""
1892
+ Returns a hypergeometric function (or linear combination of them)
1893
+ representing the given holonomic function.
1894
+
1895
+ Explanation
1896
+ ===========
1897
+
1898
+ Returns an answer of the form:
1899
+ `a_1 \cdot x^{b_1} \cdot{hyper()} + a_2 \cdot x^{b_2} \cdot{hyper()} \dots`
1900
+
1901
+ This is very useful as one can now use ``hyperexpand`` to find the
1902
+ symbolic expressions/functions.
1903
+
1904
+ Examples
1905
+ ========
1906
+
1907
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
1908
+ >>> from sympy import ZZ
1909
+ >>> from sympy import symbols
1910
+ >>> x = symbols('x')
1911
+ >>> R, Dx = DifferentialOperators(ZZ.old_poly_ring(x),'Dx')
1912
+ >>> # sin(x)
1913
+ >>> HolonomicFunction(Dx**2 + 1, x, 0, [0, 1]).to_hyper()
1914
+ x*hyper((), (3/2,), -x**2/4)
1915
+ >>> # exp(x)
1916
+ >>> HolonomicFunction(Dx - 1, x, 0, [1]).to_hyper()
1917
+ hyper((), (), x)
1918
+
1919
+ See Also
1920
+ ========
1921
+
1922
+ from_hyper, from_meijerg
1923
+ """
1924
+
1925
+ if _recur is None:
1926
+ recurrence = self.to_sequence()
1927
+ else:
1928
+ recurrence = _recur
1929
+
1930
+ if isinstance(recurrence, tuple) and len(recurrence) == 2:
1931
+ smallest_n = recurrence[1]
1932
+ recurrence = recurrence[0]
1933
+ constantpower = 0
1934
+ elif isinstance(recurrence, tuple) and len(recurrence) == 3:
1935
+ smallest_n = recurrence[2]
1936
+ constantpower = recurrence[1]
1937
+ recurrence = recurrence[0]
1938
+ elif len(recurrence) == 1 and len(recurrence[0]) == 2:
1939
+ smallest_n = recurrence[0][1]
1940
+ recurrence = recurrence[0][0]
1941
+ constantpower = 0
1942
+ elif len(recurrence) == 1 and len(recurrence[0]) == 3:
1943
+ smallest_n = recurrence[0][2]
1944
+ constantpower = recurrence[0][1]
1945
+ recurrence = recurrence[0][0]
1946
+ else:
1947
+ sol = self.to_hyper(as_list=as_list, _recur=recurrence[0])
1948
+ for i in recurrence[1:]:
1949
+ sol += self.to_hyper(as_list=as_list, _recur=i)
1950
+ return sol
1951
+
1952
+ u0 = recurrence.u0
1953
+ r = recurrence.recurrence
1954
+ x = self.x
1955
+ x0 = self.x0
1956
+
1957
+ # order of the recurrence relation
1958
+ m = r.order
1959
+
1960
+ # when no recurrence exists, and the power series have finite terms
1961
+ if m == 0:
1962
+ nonzeroterms = roots(r.parent.base.to_sympy(r.listofpoly[0]), recurrence.n, filter='R')
1963
+
1964
+ sol = S.Zero
1965
+ for j, i in enumerate(nonzeroterms):
1966
+
1967
+ if i < 0 or int(i) != i:
1968
+ continue
1969
+
1970
+ i = int(i)
1971
+ if i < len(u0):
1972
+ if isinstance(u0[i], (PolyElement, FracElement)):
1973
+ u0[i] = u0[i].as_expr()
1974
+ sol += u0[i] * x**i
1975
+
1976
+ else:
1977
+ sol += Symbol('C_%s' %j) * x**i
1978
+
1979
+ if isinstance(sol, (PolyElement, FracElement)):
1980
+ sol = sol.as_expr() * x**constantpower
1981
+ else:
1982
+ sol = sol * x**constantpower
1983
+ if as_list:
1984
+ if x0 != 0:
1985
+ return [(sol.subs(x, x - x0), )]
1986
+ return [(sol, )]
1987
+ if x0 != 0:
1988
+ return sol.subs(x, x - x0)
1989
+ return sol
1990
+
1991
+ if smallest_n + m > len(u0):
1992
+ raise NotImplementedError("Can't compute sufficient Initial Conditions")
1993
+
1994
+ # check if the recurrence represents a hypergeometric series
1995
+ is_hyper = True
1996
+
1997
+ for i in range(1, len(r.listofpoly)-1):
1998
+ if r.listofpoly[i] != r.parent.base.zero:
1999
+ is_hyper = False
2000
+ break
2001
+
2002
+ if not is_hyper:
2003
+ raise NotHyperSeriesError(self, self.x0)
2004
+
2005
+ a = r.listofpoly[0]
2006
+ b = r.listofpoly[-1]
2007
+
2008
+ # the constant multiple of argument of hypergeometric function
2009
+ if isinstance(a.rep[0], (PolyElement, FracElement)):
2010
+ c = - (S(a.rep[0].as_expr()) * m**(a.degree())) / (S(b.rep[0].as_expr()) * m**(b.degree()))
2011
+ else:
2012
+ c = - (S(a.rep[0]) * m**(a.degree())) / (S(b.rep[0]) * m**(b.degree()))
2013
+
2014
+ sol = 0
2015
+
2016
+ arg1 = roots(r.parent.base.to_sympy(a), recurrence.n)
2017
+ arg2 = roots(r.parent.base.to_sympy(b), recurrence.n)
2018
+
2019
+ # iterate through the initial conditions to find
2020
+ # the hypergeometric representation of the given
2021
+ # function.
2022
+ # The answer will be a linear combination
2023
+ # of different hypergeometric series which satisfies
2024
+ # the recurrence.
2025
+ if as_list:
2026
+ listofsol = []
2027
+ for i in range(smallest_n + m):
2028
+
2029
+ # if the recurrence relation doesn't hold for `n = i`,
2030
+ # then a Hypergeometric representation doesn't exist.
2031
+ # add the algebraic term a * x**i to the solution,
2032
+ # where a is u0[i]
2033
+ if i < smallest_n:
2034
+ if as_list:
2035
+ listofsol.append(((S(u0[i]) * x**(i+constantpower)).subs(x, x-x0), ))
2036
+ else:
2037
+ sol += S(u0[i]) * x**i
2038
+ continue
2039
+
2040
+ # if the coefficient u0[i] is zero, then the
2041
+ # independent hypergeomtric series starting with
2042
+ # x**i is not a part of the answer.
2043
+ if S(u0[i]) == 0:
2044
+ continue
2045
+
2046
+ ap = []
2047
+ bq = []
2048
+
2049
+ # substitute m * n + i for n
2050
+ for k in ordered(arg1.keys()):
2051
+ ap.extend([nsimplify((i - k) / m)] * arg1[k])
2052
+
2053
+ for k in ordered(arg2.keys()):
2054
+ bq.extend([nsimplify((i - k) / m)] * arg2[k])
2055
+
2056
+ # convention of (k + 1) in the denominator
2057
+ if 1 in bq:
2058
+ bq.remove(1)
2059
+ else:
2060
+ ap.append(1)
2061
+ if as_list:
2062
+ listofsol.append(((S(u0[i])*x**(i+constantpower)).subs(x, x-x0), (hyper(ap, bq, c*x**m)).subs(x, x-x0)))
2063
+ else:
2064
+ sol += S(u0[i]) * hyper(ap, bq, c * x**m) * x**i
2065
+ if as_list:
2066
+ return listofsol
2067
+ sol = sol * x**constantpower
2068
+ if x0 != 0:
2069
+ return sol.subs(x, x - x0)
2070
+
2071
+ return sol
2072
+
2073
+ def to_expr(self):
2074
+ """
2075
+ Converts a Holonomic Function back to elementary functions.
2076
+
2077
+ Examples
2078
+ ========
2079
+
2080
+ >>> from sympy.holonomic.holonomic import HolonomicFunction, DifferentialOperators
2081
+ >>> from sympy import ZZ
2082
+ >>> from sympy import symbols, S
2083
+ >>> x = symbols('x')
2084
+ >>> R, Dx = DifferentialOperators(ZZ.old_poly_ring(x),'Dx')
2085
+ >>> HolonomicFunction(x**2*Dx**2 + x*Dx + (x**2 - 1), x, 0, [0, S(1)/2]).to_expr()
2086
+ besselj(1, x)
2087
+ >>> HolonomicFunction((1 + x)*Dx**3 + Dx**2, x, 0, [1, 1, 1]).to_expr()
2088
+ x*log(x + 1) + log(x + 1) + 1
2089
+
2090
+ """
2091
+
2092
+ return hyperexpand(self.to_hyper()).simplify()
2093
+
2094
+ def change_ics(self, b, lenics=None):
2095
+ """
2096
+ Changes the point `x0` to ``b`` for initial conditions.
2097
+
2098
+ Examples
2099
+ ========
2100
+
2101
+ >>> from sympy.holonomic import expr_to_holonomic
2102
+ >>> from sympy import symbols, sin, exp
2103
+ >>> x = symbols('x')
2104
+
2105
+ >>> expr_to_holonomic(sin(x)).change_ics(1)
2106
+ HolonomicFunction((1) + (1)*Dx**2, x, 1, [sin(1), cos(1)])
2107
+
2108
+ >>> expr_to_holonomic(exp(x)).change_ics(2)
2109
+ HolonomicFunction((-1) + (1)*Dx, x, 2, [exp(2)])
2110
+ """
2111
+
2112
+ symbolic = True
2113
+
2114
+ if lenics is None and len(self.y0) > self.annihilator.order:
2115
+ lenics = len(self.y0)
2116
+ dom = self.annihilator.parent.base.domain
2117
+
2118
+ try:
2119
+ sol = expr_to_holonomic(self.to_expr(), x=self.x, x0=b, lenics=lenics, domain=dom)
2120
+ except (NotPowerSeriesError, NotHyperSeriesError):
2121
+ symbolic = False
2122
+
2123
+ if symbolic and sol.x0 == b:
2124
+ return sol
2125
+
2126
+ y0 = self.evalf(b, derivatives=True)
2127
+ return HolonomicFunction(self.annihilator, self.x, b, y0)
2128
+
2129
+ def to_meijerg(self):
2130
+ """
2131
+ Returns a linear combination of Meijer G-functions.
2132
+
2133
+ Examples
2134
+ ========
2135
+
2136
+ >>> from sympy.holonomic import expr_to_holonomic
2137
+ >>> from sympy import sin, cos, hyperexpand, log, symbols
2138
+ >>> x = symbols('x')
2139
+ >>> hyperexpand(expr_to_holonomic(cos(x) + sin(x)).to_meijerg())
2140
+ sin(x) + cos(x)
2141
+ >>> hyperexpand(expr_to_holonomic(log(x)).to_meijerg()).simplify()
2142
+ log(x)
2143
+
2144
+ See Also
2145
+ ========
2146
+
2147
+ to_hyper
2148
+ """
2149
+
2150
+ # convert to hypergeometric first
2151
+ rep = self.to_hyper(as_list=True)
2152
+ sol = S.Zero
2153
+
2154
+ for i in rep:
2155
+ if len(i) == 1:
2156
+ sol += i[0]
2157
+
2158
+ elif len(i) == 2:
2159
+ sol += i[0] * _hyper_to_meijerg(i[1])
2160
+
2161
+ return sol
2162
+
2163
+
2164
+ def from_hyper(func, x0=0, evalf=False):
2165
+ r"""
2166
+ Converts a hypergeometric function to holonomic.
2167
+ ``func`` is the Hypergeometric Function and ``x0`` is the point at
2168
+ which initial conditions are required.
2169
+
2170
+ Examples
2171
+ ========
2172
+
2173
+ >>> from sympy.holonomic.holonomic import from_hyper
2174
+ >>> from sympy import symbols, hyper, S
2175
+ >>> x = symbols('x')
2176
+ >>> from_hyper(hyper([], [S(3)/2], x**2/4))
2177
+ HolonomicFunction((-x) + (2)*Dx + (x)*Dx**2, x, 1, [sinh(1), -sinh(1) + cosh(1)])
2178
+ """
2179
+
2180
+ a = func.ap
2181
+ b = func.bq
2182
+ z = func.args[2]
2183
+ x = z.atoms(Symbol).pop()
2184
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
2185
+
2186
+ # generalized hypergeometric differential equation
2187
+ xDx = x*Dx
2188
+ r1 = 1
2189
+ for ai in a: # XXX gives sympify error if Mul is used with list of all factors
2190
+ r1 *= xDx + ai
2191
+ xDx_1 = xDx - 1
2192
+ # r2 = Mul(*([Dx] + [xDx_1 + bi for bi in b])) # XXX gives sympify error
2193
+ r2 = Dx
2194
+ for bi in b:
2195
+ r2 *= xDx_1 + bi
2196
+ sol = r1 - r2
2197
+
2198
+ simp = hyperexpand(func)
2199
+
2200
+ if simp in (Infinity, NegativeInfinity):
2201
+ return HolonomicFunction(sol, x).composition(z)
2202
+
2203
+ def _find_conditions(simp, x, x0, order, evalf=False):
2204
+ y0 = []
2205
+ for i in range(order):
2206
+ if evalf:
2207
+ val = simp.subs(x, x0).evalf()
2208
+ else:
2209
+ val = simp.subs(x, x0)
2210
+ # return None if it is Infinite or NaN
2211
+ if val.is_finite is False or isinstance(val, NaN):
2212
+ return None
2213
+ y0.append(val)
2214
+ simp = simp.diff(x)
2215
+ return y0
2216
+
2217
+ # if the function is known symbolically
2218
+ if not isinstance(simp, hyper):
2219
+ y0 = _find_conditions(simp, x, x0, sol.order)
2220
+ while not y0:
2221
+ # if values don't exist at 0, then try to find initial
2222
+ # conditions at 1. If it doesn't exist at 1 too then
2223
+ # try 2 and so on.
2224
+ x0 += 1
2225
+ y0 = _find_conditions(simp, x, x0, sol.order)
2226
+
2227
+ return HolonomicFunction(sol, x).composition(z, x0, y0)
2228
+
2229
+ if isinstance(simp, hyper):
2230
+ x0 = 1
2231
+ # use evalf if the function can't be simplified
2232
+ y0 = _find_conditions(simp, x, x0, sol.order, evalf)
2233
+ while not y0:
2234
+ x0 += 1
2235
+ y0 = _find_conditions(simp, x, x0, sol.order, evalf)
2236
+ return HolonomicFunction(sol, x).composition(z, x0, y0)
2237
+
2238
+ return HolonomicFunction(sol, x).composition(z)
2239
+
2240
+
2241
+ def from_meijerg(func, x0=0, evalf=False, initcond=True, domain=QQ):
2242
+ """
2243
+ Converts a Meijer G-function to Holonomic.
2244
+ ``func`` is the G-Function and ``x0`` is the point at
2245
+ which initial conditions are required.
2246
+
2247
+ Examples
2248
+ ========
2249
+
2250
+ >>> from sympy.holonomic.holonomic import from_meijerg
2251
+ >>> from sympy import symbols, meijerg, S
2252
+ >>> x = symbols('x')
2253
+ >>> from_meijerg(meijerg(([], []), ([S(1)/2], [0]), x**2/4))
2254
+ HolonomicFunction((1) + (1)*Dx**2, x, 0, [0, 1/sqrt(pi)])
2255
+ """
2256
+
2257
+ a = func.ap
2258
+ b = func.bq
2259
+ n = len(func.an)
2260
+ m = len(func.bm)
2261
+ p = len(a)
2262
+ z = func.args[2]
2263
+ x = z.atoms(Symbol).pop()
2264
+ R, Dx = DifferentialOperators(domain.old_poly_ring(x), 'Dx')
2265
+
2266
+ # compute the differential equation satisfied by the
2267
+ # Meijer G-function.
2268
+ xDx = x*Dx
2269
+ xDx1 = xDx + 1
2270
+ r1 = x*(-1)**(m + n - p)
2271
+ for ai in a: # XXX gives sympify error if args given in list
2272
+ r1 *= xDx1 - ai
2273
+ # r2 = Mul(*[xDx - bi for bi in b]) # gives sympify error
2274
+ r2 = 1
2275
+ for bi in b:
2276
+ r2 *= xDx - bi
2277
+ sol = r1 - r2
2278
+
2279
+ if not initcond:
2280
+ return HolonomicFunction(sol, x).composition(z)
2281
+
2282
+ simp = hyperexpand(func)
2283
+
2284
+ if simp in (Infinity, NegativeInfinity):
2285
+ return HolonomicFunction(sol, x).composition(z)
2286
+
2287
+ def _find_conditions(simp, x, x0, order, evalf=False):
2288
+ y0 = []
2289
+ for i in range(order):
2290
+ if evalf:
2291
+ val = simp.subs(x, x0).evalf()
2292
+ else:
2293
+ val = simp.subs(x, x0)
2294
+ if val.is_finite is False or isinstance(val, NaN):
2295
+ return None
2296
+ y0.append(val)
2297
+ simp = simp.diff(x)
2298
+ return y0
2299
+
2300
+ # computing initial conditions
2301
+ if not isinstance(simp, meijerg):
2302
+ y0 = _find_conditions(simp, x, x0, sol.order)
2303
+ while not y0:
2304
+ x0 += 1
2305
+ y0 = _find_conditions(simp, x, x0, sol.order)
2306
+
2307
+ return HolonomicFunction(sol, x).composition(z, x0, y0)
2308
+
2309
+ if isinstance(simp, meijerg):
2310
+ x0 = 1
2311
+ y0 = _find_conditions(simp, x, x0, sol.order, evalf)
2312
+ while not y0:
2313
+ x0 += 1
2314
+ y0 = _find_conditions(simp, x, x0, sol.order, evalf)
2315
+
2316
+ return HolonomicFunction(sol, x).composition(z, x0, y0)
2317
+
2318
+ return HolonomicFunction(sol, x).composition(z)
2319
+
2320
+
2321
+ x_1 = Dummy('x_1')
2322
+ _lookup_table = None
2323
+ domain_for_table = None
2324
+ from sympy.integrals.meijerint import _mytype
2325
+
2326
+
2327
+ def expr_to_holonomic(func, x=None, x0=0, y0=None, lenics=None, domain=None, initcond=True):
2328
+ """
2329
+ Converts a function or an expression to a holonomic function.
2330
+
2331
+ Parameters
2332
+ ==========
2333
+
2334
+ func:
2335
+ The expression to be converted.
2336
+ x:
2337
+ variable for the function.
2338
+ x0:
2339
+ point at which initial condition must be computed.
2340
+ y0:
2341
+ One can optionally provide initial condition if the method
2342
+ is not able to do it automatically.
2343
+ lenics:
2344
+ Number of terms in the initial condition. By default it is
2345
+ equal to the order of the annihilator.
2346
+ domain:
2347
+ Ground domain for the polynomials in ``x`` appearing as coefficients
2348
+ in the annihilator.
2349
+ initcond:
2350
+ Set it false if you do not want the initial conditions to be computed.
2351
+
2352
+ Examples
2353
+ ========
2354
+
2355
+ >>> from sympy.holonomic.holonomic import expr_to_holonomic
2356
+ >>> from sympy import sin, exp, symbols
2357
+ >>> x = symbols('x')
2358
+ >>> expr_to_holonomic(sin(x))
2359
+ HolonomicFunction((1) + (1)*Dx**2, x, 0, [0, 1])
2360
+ >>> expr_to_holonomic(exp(x))
2361
+ HolonomicFunction((-1) + (1)*Dx, x, 0, [1])
2362
+
2363
+ See Also
2364
+ ========
2365
+
2366
+ sympy.integrals.meijerint._rewrite1, _convert_poly_rat_alg, _create_table
2367
+ """
2368
+ func = sympify(func)
2369
+ syms = func.free_symbols
2370
+
2371
+ if not x:
2372
+ if len(syms) == 1:
2373
+ x= syms.pop()
2374
+ else:
2375
+ raise ValueError("Specify the variable for the function")
2376
+ elif x in syms:
2377
+ syms.remove(x)
2378
+
2379
+ extra_syms = list(syms)
2380
+
2381
+ if domain is None:
2382
+ if func.has(Float):
2383
+ domain = RR
2384
+ else:
2385
+ domain = QQ
2386
+ if len(extra_syms) != 0:
2387
+ domain = domain[extra_syms].get_field()
2388
+
2389
+ # try to convert if the function is polynomial or rational
2390
+ solpoly = _convert_poly_rat_alg(func, x, x0=x0, y0=y0, lenics=lenics, domain=domain, initcond=initcond)
2391
+ if solpoly:
2392
+ return solpoly
2393
+
2394
+ # create the lookup table
2395
+ global _lookup_table, domain_for_table
2396
+ if not _lookup_table:
2397
+ domain_for_table = domain
2398
+ _lookup_table = {}
2399
+ _create_table(_lookup_table, domain=domain)
2400
+ elif domain != domain_for_table:
2401
+ domain_for_table = domain
2402
+ _lookup_table = {}
2403
+ _create_table(_lookup_table, domain=domain)
2404
+
2405
+ # use the table directly to convert to Holonomic
2406
+ if func.is_Function:
2407
+ f = func.subs(x, x_1)
2408
+ t = _mytype(f, x_1)
2409
+ if t in _lookup_table:
2410
+ l = _lookup_table[t]
2411
+ sol = l[0][1].change_x(x)
2412
+ else:
2413
+ sol = _convert_meijerint(func, x, initcond=False, domain=domain)
2414
+ if not sol:
2415
+ raise NotImplementedError
2416
+ if y0:
2417
+ sol.y0 = y0
2418
+ if y0 or not initcond:
2419
+ sol.x0 = x0
2420
+ return sol
2421
+ if not lenics:
2422
+ lenics = sol.annihilator.order
2423
+ _y0 = _find_conditions(func, x, x0, lenics)
2424
+ while not _y0:
2425
+ x0 += 1
2426
+ _y0 = _find_conditions(func, x, x0, lenics)
2427
+ return HolonomicFunction(sol.annihilator, x, x0, _y0)
2428
+
2429
+ if y0 or not initcond:
2430
+ sol = sol.composition(func.args[0])
2431
+ if y0:
2432
+ sol.y0 = y0
2433
+ sol.x0 = x0
2434
+ return sol
2435
+ if not lenics:
2436
+ lenics = sol.annihilator.order
2437
+
2438
+ _y0 = _find_conditions(func, x, x0, lenics)
2439
+ while not _y0:
2440
+ x0 += 1
2441
+ _y0 = _find_conditions(func, x, x0, lenics)
2442
+ return sol.composition(func.args[0], x0, _y0)
2443
+
2444
+ # iterate through the expression recursively
2445
+ args = func.args
2446
+ f = func.func
2447
+ sol = expr_to_holonomic(args[0], x=x, initcond=False, domain=domain)
2448
+
2449
+ if f is Add:
2450
+ for i in range(1, len(args)):
2451
+ sol += expr_to_holonomic(args[i], x=x, initcond=False, domain=domain)
2452
+
2453
+ elif f is Mul:
2454
+ for i in range(1, len(args)):
2455
+ sol *= expr_to_holonomic(args[i], x=x, initcond=False, domain=domain)
2456
+
2457
+ elif f is Pow:
2458
+ sol = sol**args[1]
2459
+ sol.x0 = x0
2460
+ if not sol:
2461
+ raise NotImplementedError
2462
+ if y0:
2463
+ sol.y0 = y0
2464
+ if y0 or not initcond:
2465
+ return sol
2466
+ if sol.y0:
2467
+ return sol
2468
+ if not lenics:
2469
+ lenics = sol.annihilator.order
2470
+ if sol.annihilator.is_singular(x0):
2471
+ r = sol._indicial()
2472
+ l = list(r)
2473
+ if len(r) == 1 and r[l[0]] == S.One:
2474
+ r = l[0]
2475
+ g = func / (x - x0)**r
2476
+ singular_ics = _find_conditions(g, x, x0, lenics)
2477
+ singular_ics = [j / factorial(i) for i, j in enumerate(singular_ics)]
2478
+ y0 = {r:singular_ics}
2479
+ return HolonomicFunction(sol.annihilator, x, x0, y0)
2480
+
2481
+ _y0 = _find_conditions(func, x, x0, lenics)
2482
+ while not _y0:
2483
+ x0 += 1
2484
+ _y0 = _find_conditions(func, x, x0, lenics)
2485
+
2486
+ return HolonomicFunction(sol.annihilator, x, x0, _y0)
2487
+
2488
+
2489
+ ## Some helper functions ##
2490
+
2491
+ def _normalize(list_of, parent, negative=True):
2492
+ """
2493
+ Normalize a given annihilator
2494
+ """
2495
+
2496
+ num = []
2497
+ denom = []
2498
+ base = parent.base
2499
+ K = base.get_field()
2500
+ lcm_denom = base.from_sympy(S.One)
2501
+ list_of_coeff = []
2502
+
2503
+ # convert polynomials to the elements of associated
2504
+ # fraction field
2505
+ for i, j in enumerate(list_of):
2506
+ if isinstance(j, base.dtype):
2507
+ list_of_coeff.append(K.new(j.rep))
2508
+ elif not isinstance(j, K.dtype):
2509
+ list_of_coeff.append(K.from_sympy(sympify(j)))
2510
+ else:
2511
+ list_of_coeff.append(j)
2512
+
2513
+ # corresponding numerators of the sequence of polynomials
2514
+ num.append(list_of_coeff[i].numer())
2515
+
2516
+ # corresponding denominators
2517
+ denom.append(list_of_coeff[i].denom())
2518
+
2519
+ # lcm of denominators in the coefficients
2520
+ for i in denom:
2521
+ lcm_denom = i.lcm(lcm_denom)
2522
+
2523
+ if negative:
2524
+ lcm_denom = -lcm_denom
2525
+
2526
+ lcm_denom = K.new(lcm_denom.rep)
2527
+
2528
+ # multiply the coefficients with lcm
2529
+ for i, j in enumerate(list_of_coeff):
2530
+ list_of_coeff[i] = j * lcm_denom
2531
+
2532
+ gcd_numer = base((list_of_coeff[-1].numer() / list_of_coeff[-1].denom()).rep)
2533
+
2534
+ # gcd of numerators in the coefficients
2535
+ for i in num:
2536
+ gcd_numer = i.gcd(gcd_numer)
2537
+
2538
+ gcd_numer = K.new(gcd_numer.rep)
2539
+
2540
+ # divide all the coefficients by the gcd
2541
+ for i, j in enumerate(list_of_coeff):
2542
+ frac_ans = j / gcd_numer
2543
+ list_of_coeff[i] = base((frac_ans.numer() / frac_ans.denom()).rep)
2544
+
2545
+ return DifferentialOperator(list_of_coeff, parent)
2546
+
2547
+
2548
+ def _derivate_diff_eq(listofpoly):
2549
+ """
2550
+ Let a differential equation a0(x)y(x) + a1(x)y'(x) + ... = 0
2551
+ where a0, a1,... are polynomials or rational functions. The function
2552
+ returns b0, b1, b2... such that the differential equation
2553
+ b0(x)y(x) + b1(x)y'(x) +... = 0 is formed after differentiating the
2554
+ former equation.
2555
+ """
2556
+
2557
+ sol = []
2558
+ a = len(listofpoly) - 1
2559
+ sol.append(DMFdiff(listofpoly[0]))
2560
+
2561
+ for i, j in enumerate(listofpoly[1:]):
2562
+ sol.append(DMFdiff(j) + listofpoly[i])
2563
+
2564
+ sol.append(listofpoly[a])
2565
+ return sol
2566
+
2567
+
2568
+ def _hyper_to_meijerg(func):
2569
+ """
2570
+ Converts a `hyper` to meijerg.
2571
+ """
2572
+ ap = func.ap
2573
+ bq = func.bq
2574
+
2575
+ ispoly = any(i <= 0 and int(i) == i for i in ap)
2576
+ if ispoly:
2577
+ return hyperexpand(func)
2578
+
2579
+ z = func.args[2]
2580
+
2581
+ # parameters of the `meijerg` function.
2582
+ an = (1 - i for i in ap)
2583
+ anp = ()
2584
+ bm = (S.Zero, )
2585
+ bmq = (1 - i for i in bq)
2586
+
2587
+ k = S.One
2588
+
2589
+ for i in bq:
2590
+ k = k * gamma(i)
2591
+
2592
+ for i in ap:
2593
+ k = k / gamma(i)
2594
+
2595
+ return k * meijerg(an, anp, bm, bmq, -z)
2596
+
2597
+
2598
+ def _add_lists(list1, list2):
2599
+ """Takes polynomial sequences of two annihilators a and b and returns
2600
+ the list of polynomials of sum of a and b.
2601
+ """
2602
+ if len(list1) <= len(list2):
2603
+ sol = [a + b for a, b in zip(list1, list2)] + list2[len(list1):]
2604
+ else:
2605
+ sol = [a + b for a, b in zip(list1, list2)] + list1[len(list2):]
2606
+ return sol
2607
+
2608
+
2609
+ def _extend_y0(Holonomic, n):
2610
+ """
2611
+ Tries to find more initial conditions by substituting the initial
2612
+ value point in the differential equation.
2613
+ """
2614
+
2615
+ if Holonomic.annihilator.is_singular(Holonomic.x0) or Holonomic.is_singularics() == True:
2616
+ return Holonomic.y0
2617
+
2618
+ annihilator = Holonomic.annihilator
2619
+ a = annihilator.order
2620
+
2621
+ listofpoly = []
2622
+
2623
+ y0 = Holonomic.y0
2624
+ R = annihilator.parent.base
2625
+ K = R.get_field()
2626
+
2627
+ for i, j in enumerate(annihilator.listofpoly):
2628
+ if isinstance(j, annihilator.parent.base.dtype):
2629
+ listofpoly.append(K.new(j.rep))
2630
+
2631
+ if len(y0) < a or n <= len(y0):
2632
+ return y0
2633
+ else:
2634
+ list_red = [-listofpoly[i] / listofpoly[a]
2635
+ for i in range(a)]
2636
+ if len(y0) > a:
2637
+ y1 = [y0[i] for i in range(a)]
2638
+ else:
2639
+ y1 = list(y0)
2640
+ for i in range(n - a):
2641
+ sol = 0
2642
+ for a, b in zip(y1, list_red):
2643
+ r = DMFsubs(b, Holonomic.x0)
2644
+ if not getattr(r, 'is_finite', True):
2645
+ return y0
2646
+ if isinstance(r, (PolyElement, FracElement)):
2647
+ r = r.as_expr()
2648
+ sol += a * r
2649
+ y1.append(sol)
2650
+ list_red = _derivate_diff_eq(list_red)
2651
+
2652
+ return y0 + y1[len(y0):]
2653
+
2654
+
2655
+ def DMFdiff(frac):
2656
+ # differentiate a DMF object represented as p/q
2657
+ if not isinstance(frac, DMF):
2658
+ return frac.diff()
2659
+
2660
+ K = frac.ring
2661
+ p = K.numer(frac)
2662
+ q = K.denom(frac)
2663
+ sol_num = - p * q.diff() + q * p.diff()
2664
+ sol_denom = q**2
2665
+ return K((sol_num.rep, sol_denom.rep))
2666
+
2667
+
2668
+ def DMFsubs(frac, x0, mpm=False):
2669
+ # substitute the point x0 in DMF object of the form p/q
2670
+ if not isinstance(frac, DMF):
2671
+ return frac
2672
+
2673
+ p = frac.num
2674
+ q = frac.den
2675
+ sol_p = S.Zero
2676
+ sol_q = S.Zero
2677
+
2678
+ if mpm:
2679
+ from mpmath import mp
2680
+
2681
+ for i, j in enumerate(reversed(p)):
2682
+ if mpm:
2683
+ j = sympify(j)._to_mpmath(mp.prec)
2684
+ sol_p += j * x0**i
2685
+
2686
+ for i, j in enumerate(reversed(q)):
2687
+ if mpm:
2688
+ j = sympify(j)._to_mpmath(mp.prec)
2689
+ sol_q += j * x0**i
2690
+
2691
+ if isinstance(sol_p, (PolyElement, FracElement)):
2692
+ sol_p = sol_p.as_expr()
2693
+ if isinstance(sol_q, (PolyElement, FracElement)):
2694
+ sol_q = sol_q.as_expr()
2695
+
2696
+ return sol_p / sol_q
2697
+
2698
+
2699
+ def _convert_poly_rat_alg(func, x, x0=0, y0=None, lenics=None, domain=QQ, initcond=True):
2700
+ """
2701
+ Converts polynomials, rationals and algebraic functions to holonomic.
2702
+ """
2703
+
2704
+ ispoly = func.is_polynomial()
2705
+ if not ispoly:
2706
+ israt = func.is_rational_function()
2707
+ else:
2708
+ israt = True
2709
+
2710
+ if not (ispoly or israt):
2711
+ basepoly, ratexp = func.as_base_exp()
2712
+ if basepoly.is_polynomial() and ratexp.is_Number:
2713
+ if isinstance(ratexp, Float):
2714
+ ratexp = nsimplify(ratexp)
2715
+ m, n = ratexp.p, ratexp.q
2716
+ is_alg = True
2717
+ else:
2718
+ is_alg = False
2719
+ else:
2720
+ is_alg = True
2721
+
2722
+ if not (ispoly or israt or is_alg):
2723
+ return None
2724
+
2725
+ R = domain.old_poly_ring(x)
2726
+ _, Dx = DifferentialOperators(R, 'Dx')
2727
+
2728
+ # if the function is constant
2729
+ if not func.has(x):
2730
+ return HolonomicFunction(Dx, x, 0, [func])
2731
+
2732
+ if ispoly:
2733
+ # differential equation satisfied by polynomial
2734
+ sol = func * Dx - func.diff(x)
2735
+ sol = _normalize(sol.listofpoly, sol.parent, negative=False)
2736
+ is_singular = sol.is_singular(x0)
2737
+
2738
+ # try to compute the conditions for singular points
2739
+ if y0 is None and x0 == 0 and is_singular:
2740
+ rep = R.from_sympy(func).rep
2741
+ for i, j in enumerate(reversed(rep)):
2742
+ if j == 0:
2743
+ continue
2744
+ else:
2745
+ coeff = list(reversed(rep))[i:]
2746
+ indicial = i
2747
+ break
2748
+ for i, j in enumerate(coeff):
2749
+ if isinstance(j, (PolyElement, FracElement)):
2750
+ coeff[i] = j.as_expr()
2751
+ y0 = {indicial: S(coeff)}
2752
+
2753
+ elif israt:
2754
+ p, q = func.as_numer_denom()
2755
+ # differential equation satisfied by rational
2756
+ sol = p * q * Dx + p * q.diff(x) - q * p.diff(x)
2757
+ sol = _normalize(sol.listofpoly, sol.parent, negative=False)
2758
+
2759
+ elif is_alg:
2760
+ sol = n * (x / m) * Dx - 1
2761
+ sol = HolonomicFunction(sol, x).composition(basepoly).annihilator
2762
+ is_singular = sol.is_singular(x0)
2763
+
2764
+ # try to compute the conditions for singular points
2765
+ if y0 is None and x0 == 0 and is_singular and \
2766
+ (lenics is None or lenics <= 1):
2767
+ rep = R.from_sympy(basepoly).rep
2768
+ for i, j in enumerate(reversed(rep)):
2769
+ if j == 0:
2770
+ continue
2771
+ if isinstance(j, (PolyElement, FracElement)):
2772
+ j = j.as_expr()
2773
+
2774
+ coeff = S(j)**ratexp
2775
+ indicial = S(i) * ratexp
2776
+ break
2777
+ if isinstance(coeff, (PolyElement, FracElement)):
2778
+ coeff = coeff.as_expr()
2779
+ y0 = {indicial: S([coeff])}
2780
+
2781
+ if y0 or not initcond:
2782
+ return HolonomicFunction(sol, x, x0, y0)
2783
+
2784
+ if not lenics:
2785
+ lenics = sol.order
2786
+
2787
+ if sol.is_singular(x0):
2788
+ r = HolonomicFunction(sol, x, x0)._indicial()
2789
+ l = list(r)
2790
+ if len(r) == 1 and r[l[0]] == S.One:
2791
+ r = l[0]
2792
+ g = func / (x - x0)**r
2793
+ singular_ics = _find_conditions(g, x, x0, lenics)
2794
+ singular_ics = [j / factorial(i) for i, j in enumerate(singular_ics)]
2795
+ y0 = {r:singular_ics}
2796
+ return HolonomicFunction(sol, x, x0, y0)
2797
+
2798
+ y0 = _find_conditions(func, x, x0, lenics)
2799
+ while not y0:
2800
+ x0 += 1
2801
+ y0 = _find_conditions(func, x, x0, lenics)
2802
+
2803
+ return HolonomicFunction(sol, x, x0, y0)
2804
+
2805
+
2806
+ def _convert_meijerint(func, x, initcond=True, domain=QQ):
2807
+ args = meijerint._rewrite1(func, x)
2808
+
2809
+ if args:
2810
+ fac, po, g, _ = args
2811
+ else:
2812
+ return None
2813
+
2814
+ # lists for sum of meijerg functions
2815
+ fac_list = [fac * i[0] for i in g]
2816
+ t = po.as_base_exp()
2817
+ s = t[1] if t[0] == x else S.Zero
2818
+ po_list = [s + i[1] for i in g]
2819
+ G_list = [i[2] for i in g]
2820
+
2821
+ # finds meijerg representation of x**s * meijerg(a1 ... ap, b1 ... bq, z)
2822
+ def _shift(func, s):
2823
+ z = func.args[-1]
2824
+ if z.has(I):
2825
+ z = z.subs(exp_polar, exp)
2826
+
2827
+ d = z.collect(x, evaluate=False)
2828
+ b = list(d)[0]
2829
+ a = d[b]
2830
+
2831
+ t = b.as_base_exp()
2832
+ b = t[1] if t[0] == x else S.Zero
2833
+ r = s / b
2834
+ an = (i + r for i in func.args[0][0])
2835
+ ap = (i + r for i in func.args[0][1])
2836
+ bm = (i + r for i in func.args[1][0])
2837
+ bq = (i + r for i in func.args[1][1])
2838
+
2839
+ return a**-r, meijerg((an, ap), (bm, bq), z)
2840
+
2841
+ coeff, m = _shift(G_list[0], po_list[0])
2842
+ sol = fac_list[0] * coeff * from_meijerg(m, initcond=initcond, domain=domain)
2843
+
2844
+ # add all the meijerg functions after converting to holonomic
2845
+ for i in range(1, len(G_list)):
2846
+ coeff, m = _shift(G_list[i], po_list[i])
2847
+ sol += fac_list[i] * coeff * from_meijerg(m, initcond=initcond, domain=domain)
2848
+
2849
+ return sol
2850
+
2851
+
2852
+ def _create_table(table, domain=QQ):
2853
+ """
2854
+ Creates the look-up table. For a similar implementation
2855
+ see meijerint._create_lookup_table.
2856
+ """
2857
+
2858
+ def add(formula, annihilator, arg, x0=0, y0=()):
2859
+ """
2860
+ Adds a formula in the dictionary
2861
+ """
2862
+ table.setdefault(_mytype(formula, x_1), []).append((formula,
2863
+ HolonomicFunction(annihilator, arg, x0, y0)))
2864
+
2865
+ R = domain.old_poly_ring(x_1)
2866
+ _, Dx = DifferentialOperators(R, 'Dx')
2867
+
2868
+ # add some basic functions
2869
+ add(sin(x_1), Dx**2 + 1, x_1, 0, [0, 1])
2870
+ add(cos(x_1), Dx**2 + 1, x_1, 0, [1, 0])
2871
+ add(exp(x_1), Dx - 1, x_1, 0, 1)
2872
+ add(log(x_1), Dx + x_1*Dx**2, x_1, 1, [0, 1])
2873
+
2874
+ add(erf(x_1), 2*x_1*Dx + Dx**2, x_1, 0, [0, 2/sqrt(pi)])
2875
+ add(erfc(x_1), 2*x_1*Dx + Dx**2, x_1, 0, [1, -2/sqrt(pi)])
2876
+ add(erfi(x_1), -2*x_1*Dx + Dx**2, x_1, 0, [0, 2/sqrt(pi)])
2877
+
2878
+ add(sinh(x_1), Dx**2 - 1, x_1, 0, [0, 1])
2879
+ add(cosh(x_1), Dx**2 - 1, x_1, 0, [1, 0])
2880
+
2881
+ add(sinc(x_1), x_1 + 2*Dx + x_1*Dx**2, x_1)
2882
+
2883
+ add(Si(x_1), x_1*Dx + 2*Dx**2 + x_1*Dx**3, x_1)
2884
+ add(Ci(x_1), x_1*Dx + 2*Dx**2 + x_1*Dx**3, x_1)
2885
+
2886
+ add(Shi(x_1), -x_1*Dx + 2*Dx**2 + x_1*Dx**3, x_1)
2887
+
2888
+
2889
+ def _find_conditions(func, x, x0, order):
2890
+ y0 = []
2891
+ for i in range(order):
2892
+ val = func.subs(x, x0)
2893
+ if isinstance(val, NaN):
2894
+ val = limit(func, x, x0)
2895
+ if val.is_finite is False or isinstance(val, NaN):
2896
+ return None
2897
+ y0.append(val)
2898
+ func = func.diff(x)
2899
+ return y0
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/holonomicerrors.py ADDED
@@ -0,0 +1,49 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """ Common Exceptions for `holonomic` module. """
2
+
3
+ class BaseHolonomicError(Exception):
4
+
5
+ def new(self, *args):
6
+ raise NotImplementedError("abstract base class")
7
+
8
+ class NotPowerSeriesError(BaseHolonomicError):
9
+
10
+ def __init__(self, holonomic, x0):
11
+ self.holonomic = holonomic
12
+ self.x0 = x0
13
+
14
+ def __str__(self):
15
+ s = 'A Power Series does not exists for '
16
+ s += str(self.holonomic)
17
+ s += ' about %s.' %self.x0
18
+ return s
19
+
20
+ class NotHolonomicError(BaseHolonomicError):
21
+
22
+ def __init__(self, m):
23
+ self.m = m
24
+
25
+ def __str__(self):
26
+ return self.m
27
+
28
+ class SingularityError(BaseHolonomicError):
29
+
30
+ def __init__(self, holonomic, x0):
31
+ self.holonomic = holonomic
32
+ self.x0 = x0
33
+
34
+ def __str__(self):
35
+ s = str(self.holonomic)
36
+ s += ' has a singularity at %s.' %self.x0
37
+ return s
38
+
39
+ class NotHyperSeriesError(BaseHolonomicError):
40
+
41
+ def __init__(self, holonomic, x0):
42
+ self.holonomic = holonomic
43
+ self.x0 = x0
44
+
45
+ def __str__(self):
46
+ s = 'Power series expansion of '
47
+ s += str(self.holonomic)
48
+ s += ' about %s is not hypergeometric' %self.x0
49
+ return s
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/numerical.py ADDED
@@ -0,0 +1,109 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """Numerical Methods for Holonomic Functions"""
2
+
3
+ from sympy.core.sympify import sympify
4
+ from sympy.holonomic.holonomic import DMFsubs
5
+
6
+ from mpmath import mp
7
+
8
+
9
+ def _evalf(func, points, derivatives=False, method='RK4'):
10
+ """
11
+ Numerical methods for numerical integration along a given set of
12
+ points in the complex plane.
13
+ """
14
+
15
+ ann = func.annihilator
16
+ a = ann.order
17
+ R = ann.parent.base
18
+ K = R.get_field()
19
+
20
+ if method == 'Euler':
21
+ meth = _euler
22
+ else:
23
+ meth = _rk4
24
+
25
+ dmf = []
26
+ for j in ann.listofpoly:
27
+ dmf.append(K.new(j.rep))
28
+
29
+ red = [-dmf[i] / dmf[a] for i in range(a)]
30
+
31
+ y0 = func.y0
32
+ if len(y0) < a:
33
+ raise TypeError("Not Enough Initial Conditions")
34
+ x0 = func.x0
35
+ sol = [meth(red, x0, points[0], y0, a)]
36
+
37
+ for i, j in enumerate(points[1:]):
38
+ sol.append(meth(red, points[i], j, sol[-1], a))
39
+
40
+ if not derivatives:
41
+ return [sympify(i[0]) for i in sol]
42
+ else:
43
+ return sympify(sol)
44
+
45
+
46
+ def _euler(red, x0, x1, y0, a):
47
+ """
48
+ Euler's method for numerical integration.
49
+ From x0 to x1 with initial values given at x0 as vector y0.
50
+ """
51
+
52
+ A = sympify(x0)._to_mpmath(mp.prec)
53
+ B = sympify(x1)._to_mpmath(mp.prec)
54
+ y_0 = [sympify(i)._to_mpmath(mp.prec) for i in y0]
55
+ h = B - A
56
+ f_0 = y_0[1:]
57
+ f_0_n = 0
58
+
59
+ for i in range(a):
60
+ f_0_n += sympify(DMFsubs(red[i], A, mpm=True))._to_mpmath(mp.prec) * y_0[i]
61
+ f_0.append(f_0_n)
62
+
63
+ sol = []
64
+ for i in range(a):
65
+ sol.append(y_0[i] + h * f_0[i])
66
+
67
+ return sol
68
+
69
+
70
+ def _rk4(red, x0, x1, y0, a):
71
+ """
72
+ Runge-Kutta 4th order numerical method.
73
+ """
74
+
75
+ A = sympify(x0)._to_mpmath(mp.prec)
76
+ B = sympify(x1)._to_mpmath(mp.prec)
77
+ y_0 = [sympify(i)._to_mpmath(mp.prec) for i in y0]
78
+ h = B - A
79
+
80
+ f_0_n = 0
81
+ f_1_n = 0
82
+ f_2_n = 0
83
+ f_3_n = 0
84
+
85
+ f_0 = y_0[1:]
86
+ for i in range(a):
87
+ f_0_n += sympify(DMFsubs(red[i], A, mpm=True))._to_mpmath(mp.prec) * y_0[i]
88
+ f_0.append(f_0_n)
89
+
90
+ f_1 = [y_0[i] + f_0[i]*h/2 for i in range(1, a)]
91
+ for i in range(a):
92
+ f_1_n += sympify(DMFsubs(red[i], A + h/2, mpm=True))._to_mpmath(mp.prec) * (y_0[i] + f_0[i]*h/2)
93
+ f_1.append(f_1_n)
94
+
95
+ f_2 = [y_0[i] + f_1[i]*h/2 for i in range(1, a)]
96
+ for i in range(a):
97
+ f_2_n += sympify(DMFsubs(red[i], A + h/2, mpm=True))._to_mpmath(mp.prec) * (y_0[i] + f_1[i]*h/2)
98
+ f_2.append(f_2_n)
99
+
100
+ f_3 = [y_0[i] + f_2[i]*h for i in range(1, a)]
101
+ for i in range(a):
102
+ f_3_n += sympify(DMFsubs(red[i], A + h, mpm=True))._to_mpmath(mp.prec) * (y_0[i] + f_2[i]*h)
103
+ f_3.append(f_3_n)
104
+
105
+ sol = []
106
+ for i in range(a):
107
+ sol.append(y_0[i] + h * (f_0[i]+2*f_1[i]+2*f_2[i]+f_3[i])/6)
108
+
109
+ return sol
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/recurrence.py ADDED
@@ -0,0 +1,365 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """Recurrence Operators"""
2
+
3
+ from sympy.core.singleton import S
4
+ from sympy.core.symbol import (Symbol, symbols)
5
+ from sympy.printing import sstr
6
+ from sympy.core.sympify import sympify
7
+
8
+
9
+ def RecurrenceOperators(base, generator):
10
+ """
11
+ Returns an Algebra of Recurrence Operators and the operator for
12
+ shifting i.e. the `Sn` operator.
13
+ The first argument needs to be the base polynomial ring for the algebra
14
+ and the second argument must be a generator which can be either a
15
+ noncommutative Symbol or a string.
16
+
17
+ Examples
18
+ ========
19
+
20
+ >>> from sympy import ZZ
21
+ >>> from sympy import symbols
22
+ >>> from sympy.holonomic.recurrence import RecurrenceOperators
23
+ >>> n = symbols('n', integer=True)
24
+ >>> R, Sn = RecurrenceOperators(ZZ.old_poly_ring(n), 'Sn')
25
+ """
26
+
27
+ ring = RecurrenceOperatorAlgebra(base, generator)
28
+ return (ring, ring.shift_operator)
29
+
30
+
31
+ class RecurrenceOperatorAlgebra:
32
+ """
33
+ A Recurrence Operator Algebra is a set of noncommutative polynomials
34
+ in intermediate `Sn` and coefficients in a base ring A. It follows the
35
+ commutation rule:
36
+ Sn * a(n) = a(n + 1) * Sn
37
+
38
+ This class represents a Recurrence Operator Algebra and serves as the parent ring
39
+ for Recurrence Operators.
40
+
41
+ Examples
42
+ ========
43
+
44
+ >>> from sympy import ZZ
45
+ >>> from sympy import symbols
46
+ >>> from sympy.holonomic.recurrence import RecurrenceOperators
47
+ >>> n = symbols('n', integer=True)
48
+ >>> R, Sn = RecurrenceOperators(ZZ.old_poly_ring(n), 'Sn')
49
+ >>> R
50
+ Univariate Recurrence Operator Algebra in intermediate Sn over the base ring
51
+ ZZ[n]
52
+
53
+ See Also
54
+ ========
55
+
56
+ RecurrenceOperator
57
+ """
58
+
59
+ def __init__(self, base, generator):
60
+ # the base ring for the algebra
61
+ self.base = base
62
+ # the operator representing shift i.e. `Sn`
63
+ self.shift_operator = RecurrenceOperator(
64
+ [base.zero, base.one], self)
65
+
66
+ if generator is None:
67
+ self.gen_symbol = symbols('Sn', commutative=False)
68
+ else:
69
+ if isinstance(generator, str):
70
+ self.gen_symbol = symbols(generator, commutative=False)
71
+ elif isinstance(generator, Symbol):
72
+ self.gen_symbol = generator
73
+
74
+ def __str__(self):
75
+ string = 'Univariate Recurrence Operator Algebra in intermediate '\
76
+ + sstr(self.gen_symbol) + ' over the base ring ' + \
77
+ (self.base).__str__()
78
+
79
+ return string
80
+
81
+ __repr__ = __str__
82
+
83
+ def __eq__(self, other):
84
+ if self.base == other.base and self.gen_symbol == other.gen_symbol:
85
+ return True
86
+ else:
87
+ return False
88
+
89
+
90
+ def _add_lists(list1, list2):
91
+ if len(list1) <= len(list2):
92
+ sol = [a + b for a, b in zip(list1, list2)] + list2[len(list1):]
93
+ else:
94
+ sol = [a + b for a, b in zip(list1, list2)] + list1[len(list2):]
95
+ return sol
96
+
97
+
98
+ class RecurrenceOperator:
99
+ """
100
+ The Recurrence Operators are defined by a list of polynomials
101
+ in the base ring and the parent ring of the Operator.
102
+
103
+ Explanation
104
+ ===========
105
+
106
+ Takes a list of polynomials for each power of Sn and the
107
+ parent ring which must be an instance of RecurrenceOperatorAlgebra.
108
+
109
+ A Recurrence Operator can be created easily using
110
+ the operator `Sn`. See examples below.
111
+
112
+ Examples
113
+ ========
114
+
115
+ >>> from sympy.holonomic.recurrence import RecurrenceOperator, RecurrenceOperators
116
+ >>> from sympy import ZZ
117
+ >>> from sympy import symbols
118
+ >>> n = symbols('n', integer=True)
119
+ >>> R, Sn = RecurrenceOperators(ZZ.old_poly_ring(n),'Sn')
120
+
121
+ >>> RecurrenceOperator([0, 1, n**2], R)
122
+ (1)Sn + (n**2)Sn**2
123
+
124
+ >>> Sn*n
125
+ (n + 1)Sn
126
+
127
+ >>> n*Sn*n + 1 - Sn**2*n
128
+ (1) + (n**2 + n)Sn + (-n - 2)Sn**2
129
+
130
+ See Also
131
+ ========
132
+
133
+ DifferentialOperatorAlgebra
134
+ """
135
+
136
+ _op_priority = 20
137
+
138
+ def __init__(self, list_of_poly, parent):
139
+ # the parent ring for this operator
140
+ # must be an RecurrenceOperatorAlgebra object
141
+ self.parent = parent
142
+ # sequence of polynomials in n for each power of Sn
143
+ # represents the operator
144
+ # convert the expressions into ring elements using from_sympy
145
+ if isinstance(list_of_poly, list):
146
+ for i, j in enumerate(list_of_poly):
147
+ if isinstance(j, int):
148
+ list_of_poly[i] = self.parent.base.from_sympy(S(j))
149
+ elif not isinstance(j, self.parent.base.dtype):
150
+ list_of_poly[i] = self.parent.base.from_sympy(j)
151
+
152
+ self.listofpoly = list_of_poly
153
+ self.order = len(self.listofpoly) - 1
154
+
155
+ def __mul__(self, other):
156
+ """
157
+ Multiplies two Operators and returns another
158
+ RecurrenceOperator instance using the commutation rule
159
+ Sn * a(n) = a(n + 1) * Sn
160
+ """
161
+
162
+ listofself = self.listofpoly
163
+ base = self.parent.base
164
+
165
+ if not isinstance(other, RecurrenceOperator):
166
+ if not isinstance(other, self.parent.base.dtype):
167
+ listofother = [self.parent.base.from_sympy(sympify(other))]
168
+
169
+ else:
170
+ listofother = [other]
171
+ else:
172
+ listofother = other.listofpoly
173
+ # multiply a polynomial `b` with a list of polynomials
174
+
175
+ def _mul_dmp_diffop(b, listofother):
176
+ if isinstance(listofother, list):
177
+ sol = []
178
+ for i in listofother:
179
+ sol.append(i * b)
180
+ return sol
181
+ else:
182
+ return [b * listofother]
183
+
184
+ sol = _mul_dmp_diffop(listofself[0], listofother)
185
+
186
+ # compute Sn^i * b
187
+ def _mul_Sni_b(b):
188
+ sol = [base.zero]
189
+
190
+ if isinstance(b, list):
191
+ for i in b:
192
+ j = base.to_sympy(i).subs(base.gens[0], base.gens[0] + S.One)
193
+ sol.append(base.from_sympy(j))
194
+
195
+ else:
196
+ j = b.subs(base.gens[0], base.gens[0] + S.One)
197
+ sol.append(base.from_sympy(j))
198
+
199
+ return sol
200
+
201
+ for i in range(1, len(listofself)):
202
+ # find Sn^i * b in ith iteration
203
+ listofother = _mul_Sni_b(listofother)
204
+ # solution = solution + listofself[i] * (Sn^i * b)
205
+ sol = _add_lists(sol, _mul_dmp_diffop(listofself[i], listofother))
206
+
207
+ return RecurrenceOperator(sol, self.parent)
208
+
209
+ def __rmul__(self, other):
210
+ if not isinstance(other, RecurrenceOperator):
211
+
212
+ if isinstance(other, int):
213
+ other = S(other)
214
+
215
+ if not isinstance(other, self.parent.base.dtype):
216
+ other = (self.parent.base).from_sympy(other)
217
+
218
+ sol = []
219
+ for j in self.listofpoly:
220
+ sol.append(other * j)
221
+
222
+ return RecurrenceOperator(sol, self.parent)
223
+
224
+ def __add__(self, other):
225
+ if isinstance(other, RecurrenceOperator):
226
+
227
+ sol = _add_lists(self.listofpoly, other.listofpoly)
228
+ return RecurrenceOperator(sol, self.parent)
229
+
230
+ else:
231
+
232
+ if isinstance(other, int):
233
+ other = S(other)
234
+ list_self = self.listofpoly
235
+ if not isinstance(other, self.parent.base.dtype):
236
+ list_other = [((self.parent).base).from_sympy(other)]
237
+ else:
238
+ list_other = [other]
239
+ sol = []
240
+ sol.append(list_self[0] + list_other[0])
241
+ sol += list_self[1:]
242
+
243
+ return RecurrenceOperator(sol, self.parent)
244
+
245
+ __radd__ = __add__
246
+
247
+ def __sub__(self, other):
248
+ return self + (-1) * other
249
+
250
+ def __rsub__(self, other):
251
+ return (-1) * self + other
252
+
253
+ def __pow__(self, n):
254
+ if n == 1:
255
+ return self
256
+ if n == 0:
257
+ return RecurrenceOperator([self.parent.base.one], self.parent)
258
+ # if self is `Sn`
259
+ if self.listofpoly == self.parent.shift_operator.listofpoly:
260
+ sol = []
261
+ for i in range(0, n):
262
+ sol.append(self.parent.base.zero)
263
+ sol.append(self.parent.base.one)
264
+
265
+ return RecurrenceOperator(sol, self.parent)
266
+
267
+ else:
268
+ if n % 2 == 1:
269
+ powreduce = self**(n - 1)
270
+ return powreduce * self
271
+ elif n % 2 == 0:
272
+ powreduce = self**(n / 2)
273
+ return powreduce * powreduce
274
+
275
+ def __str__(self):
276
+ listofpoly = self.listofpoly
277
+ print_str = ''
278
+
279
+ for i, j in enumerate(listofpoly):
280
+ if j == self.parent.base.zero:
281
+ continue
282
+
283
+ if i == 0:
284
+ print_str += '(' + sstr(j) + ')'
285
+ continue
286
+
287
+ if print_str:
288
+ print_str += ' + '
289
+
290
+ if i == 1:
291
+ print_str += '(' + sstr(j) + ')Sn'
292
+ continue
293
+
294
+ print_str += '(' + sstr(j) + ')' + 'Sn**' + sstr(i)
295
+
296
+ return print_str
297
+
298
+ __repr__ = __str__
299
+
300
+ def __eq__(self, other):
301
+ if isinstance(other, RecurrenceOperator):
302
+ if self.listofpoly == other.listofpoly and self.parent == other.parent:
303
+ return True
304
+ else:
305
+ return False
306
+ else:
307
+ if self.listofpoly[0] == other:
308
+ for i in self.listofpoly[1:]:
309
+ if i is not self.parent.base.zero:
310
+ return False
311
+ return True
312
+ else:
313
+ return False
314
+
315
+
316
+ class HolonomicSequence:
317
+ """
318
+ A Holonomic Sequence is a type of sequence satisfying a linear homogeneous
319
+ recurrence relation with Polynomial coefficients. Alternatively, A sequence
320
+ is Holonomic if and only if its generating function is a Holonomic Function.
321
+ """
322
+
323
+ def __init__(self, recurrence, u0=[]):
324
+ self.recurrence = recurrence
325
+ if not isinstance(u0, list):
326
+ self.u0 = [u0]
327
+ else:
328
+ self.u0 = u0
329
+
330
+ if len(self.u0) == 0:
331
+ self._have_init_cond = False
332
+ else:
333
+ self._have_init_cond = True
334
+ self.n = recurrence.parent.base.gens[0]
335
+
336
+ def __repr__(self):
337
+ str_sol = 'HolonomicSequence(%s, %s)' % ((self.recurrence).__repr__(), sstr(self.n))
338
+ if not self._have_init_cond:
339
+ return str_sol
340
+ else:
341
+ cond_str = ''
342
+ seq_str = 0
343
+ for i in self.u0:
344
+ cond_str += ', u(%s) = %s' % (sstr(seq_str), sstr(i))
345
+ seq_str += 1
346
+
347
+ sol = str_sol + cond_str
348
+ return sol
349
+
350
+ __str__ = __repr__
351
+
352
+ def __eq__(self, other):
353
+ if self.recurrence == other.recurrence:
354
+ if self.n == other.n:
355
+ if self._have_init_cond and other._have_init_cond:
356
+ if self.u0 == other.u0:
357
+ return True
358
+ else:
359
+ return False
360
+ else:
361
+ return True
362
+ else:
363
+ return False
364
+ else:
365
+ return False
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/__init__.py ADDED
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llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/test_holonomic.py ADDED
@@ -0,0 +1,830 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.holonomic import (DifferentialOperator, HolonomicFunction,
2
+ DifferentialOperators, from_hyper,
3
+ from_meijerg, expr_to_holonomic)
4
+ from sympy.holonomic.recurrence import RecurrenceOperators, HolonomicSequence
5
+ from sympy.core import EulerGamma
6
+ from sympy.core.numbers import (I, Rational, pi)
7
+ from sympy.core.singleton import S
8
+ from sympy.core.symbol import (Symbol, symbols)
9
+ from sympy.functions.elementary.exponential import (exp, log)
10
+ from sympy.functions.elementary.hyperbolic import (asinh, cosh)
11
+ from sympy.functions.elementary.miscellaneous import sqrt
12
+ from sympy.functions.elementary.trigonometric import (cos, sin)
13
+ from sympy.functions.special.bessel import besselj
14
+ from sympy.functions.special.beta_functions import beta
15
+ from sympy.functions.special.error_functions import (Ci, Si, erf, erfc)
16
+ from sympy.functions.special.gamma_functions import gamma
17
+ from sympy.functions.special.hyper import (hyper, meijerg)
18
+ from sympy.printing.str import sstr
19
+ from sympy.series.order import O
20
+ from sympy.simplify.hyperexpand import hyperexpand
21
+ from sympy.polys.domains.integerring import ZZ
22
+ from sympy.polys.domains.rationalfield import QQ
23
+ from sympy.polys.domains.realfield import RR
24
+
25
+
26
+ def test_DifferentialOperator():
27
+ x = symbols('x')
28
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
29
+ assert Dx == R.derivative_operator
30
+ assert Dx == DifferentialOperator([R.base.zero, R.base.one], R)
31
+ assert x * Dx + x**2 * Dx**2 == DifferentialOperator([0, x, x**2], R)
32
+ assert (x**2 + 1) + Dx + x * \
33
+ Dx**5 == DifferentialOperator([x**2 + 1, 1, 0, 0, 0, x], R)
34
+ assert (x * Dx + x**2 + 1 - Dx * (x**3 + x))**3 == (-48 * x**6) + \
35
+ (-57 * x**7) * Dx + (-15 * x**8) * Dx**2 + (-x**9) * Dx**3
36
+ p = (x * Dx**2 + (x**2 + 3) * Dx**5) * (Dx + x**2)
37
+ q = (2 * x) + (4 * x**2) * Dx + (x**3) * Dx**2 + \
38
+ (20 * x**2 + x + 60) * Dx**3 + (10 * x**3 + 30 * x) * Dx**4 + \
39
+ (x**4 + 3 * x**2) * Dx**5 + (x**2 + 3) * Dx**6
40
+ assert p == q
41
+
42
+
43
+ def test_HolonomicFunction_addition():
44
+ x = symbols('x')
45
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
46
+ p = HolonomicFunction(Dx**2 * x, x)
47
+ q = HolonomicFunction((2) * Dx + (x) * Dx**2, x)
48
+ assert p == q
49
+ p = HolonomicFunction(x * Dx + 1, x)
50
+ q = HolonomicFunction(Dx + 1, x)
51
+ r = HolonomicFunction((x - 2) + (x**2 - 2) * Dx + (x**2 - x) * Dx**2, x)
52
+ assert p + q == r
53
+ p = HolonomicFunction(x * Dx + Dx**2 * (x**2 + 2), x)
54
+ q = HolonomicFunction(Dx - 3, x)
55
+ r = HolonomicFunction((-54 * x**2 - 126 * x - 150) + (-135 * x**3 - 252 * x**2 - 270 * x + 140) * Dx +\
56
+ (-27 * x**4 - 24 * x**2 + 14 * x - 150) * Dx**2 + \
57
+ (9 * x**4 + 15 * x**3 + 38 * x**2 + 30 * x +40) * Dx**3, x)
58
+ assert p + q == r
59
+ p = HolonomicFunction(Dx**5 - 1, x)
60
+ q = HolonomicFunction(x**3 + Dx, x)
61
+ r = HolonomicFunction((-x**18 + 45*x**14 - 525*x**10 + 1575*x**6 - x**3 - 630*x**2) + \
62
+ (-x**15 + 30*x**11 - 195*x**7 + 210*x**3 - 1)*Dx + (x**18 - 45*x**14 + 525*x**10 - \
63
+ 1575*x**6 + x**3 + 630*x**2)*Dx**5 + (x**15 - 30*x**11 + 195*x**7 - 210*x**3 + \
64
+ 1)*Dx**6, x)
65
+ assert p+q == r
66
+
67
+ p = x**2 + 3*x + 8
68
+ q = x**3 - 7*x + 5
69
+ p = p*Dx - p.diff()
70
+ q = q*Dx - q.diff()
71
+ r = HolonomicFunction(p, x) + HolonomicFunction(q, x)
72
+ s = HolonomicFunction((6*x**2 + 18*x + 14) + (-4*x**3 - 18*x**2 - 62*x + 10)*Dx +\
73
+ (x**4 + 6*x**3 + 31*x**2 - 10*x - 71)*Dx**2, x)
74
+ assert r == s
75
+
76
+
77
+ def test_HolonomicFunction_multiplication():
78
+ x = symbols('x')
79
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
80
+ p = HolonomicFunction(Dx+x+x*Dx**2, x)
81
+ q = HolonomicFunction(x*Dx+Dx*x+Dx**2, x)
82
+ r = HolonomicFunction((8*x**6 + 4*x**4 + 6*x**2 + 3) + (24*x**5 - 4*x**3 + 24*x)*Dx + \
83
+ (8*x**6 + 20*x**4 + 12*x**2 + 2)*Dx**2 + (8*x**5 + 4*x**3 + 4*x)*Dx**3 + \
84
+ (2*x**4 + x**2)*Dx**4, x)
85
+ assert p*q == r
86
+ p = HolonomicFunction(Dx**2+1, x)
87
+ q = HolonomicFunction(Dx-1, x)
88
+ r = HolonomicFunction((2) + (-2)*Dx + (1)*Dx**2, x)
89
+ assert p*q == r
90
+ p = HolonomicFunction(Dx**2+1+x+Dx, x)
91
+ q = HolonomicFunction((Dx*x-1)**2, x)
92
+ r = HolonomicFunction((4*x**7 + 11*x**6 + 16*x**5 + 4*x**4 - 6*x**3 - 7*x**2 - 8*x - 2) + \
93
+ (8*x**6 + 26*x**5 + 24*x**4 - 3*x**3 - 11*x**2 - 6*x - 2)*Dx + \
94
+ (8*x**6 + 18*x**5 + 15*x**4 - 3*x**3 - 6*x**2 - 6*x - 2)*Dx**2 + (8*x**5 + \
95
+ 10*x**4 + 6*x**3 - 2*x**2 - 4*x)*Dx**3 + (4*x**5 + 3*x**4 - x**2)*Dx**4, x)
96
+ assert p*q == r
97
+ p = HolonomicFunction(x*Dx**2-1, x)
98
+ q = HolonomicFunction(Dx*x-x, x)
99
+ r = HolonomicFunction((x - 3) + (-2*x + 2)*Dx + (x)*Dx**2, x)
100
+ assert p*q == r
101
+
102
+
103
+ def test_addition_initial_condition():
104
+ x = symbols('x')
105
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
106
+ p = HolonomicFunction(Dx-1, x, 0, [3])
107
+ q = HolonomicFunction(Dx**2+1, x, 0, [1, 0])
108
+ r = HolonomicFunction(-1 + Dx - Dx**2 + Dx**3, x, 0, [4, 3, 2])
109
+ assert p + q == r
110
+ p = HolonomicFunction(Dx - x + Dx**2, x, 0, [1, 2])
111
+ q = HolonomicFunction(Dx**2 + x, x, 0, [1, 0])
112
+ r = HolonomicFunction((-x**4 - x**3/4 - x**2 + Rational(1, 4)) + (x**3 + x**2/4 + x*Rational(3, 4) + 1)*Dx + \
113
+ (x*Rational(-3, 2) + Rational(7, 4))*Dx**2 + (x**2 - x*Rational(7, 4) + Rational(1, 4))*Dx**3 + (x**2 + x/4 + S.Half)*Dx**4, x, 0, [2, 2, -2, 2])
114
+ assert p + q == r
115
+ p = HolonomicFunction(Dx**2 + 4*x*Dx + x**2, x, 0, [3, 4])
116
+ q = HolonomicFunction(Dx**2 + 1, x, 0, [1, 1])
117
+ r = HolonomicFunction((x**6 + 2*x**4 - 5*x**2 - 6) + (4*x**5 + 36*x**3 - 32*x)*Dx + \
118
+ (x**6 + 3*x**4 + 5*x**2 - 9)*Dx**2 + (4*x**5 + 36*x**3 - 32*x)*Dx**3 + (x**4 + \
119
+ 10*x**2 - 3)*Dx**4, x, 0, [4, 5, -1, -17])
120
+ assert p + q == r
121
+ q = HolonomicFunction(Dx**3 + x, x, 2, [3, 0, 1])
122
+ p = HolonomicFunction(Dx - 1, x, 2, [1])
123
+ r = HolonomicFunction((-x**2 - x + 1) + (x**2 + x)*Dx + (-x - 2)*Dx**3 + \
124
+ (x + 1)*Dx**4, x, 2, [4, 1, 2, -5 ])
125
+ assert p + q == r
126
+ p = expr_to_holonomic(sin(x))
127
+ q = expr_to_holonomic(1/x, x0=1)
128
+ r = HolonomicFunction((x**2 + 6) + (x**3 + 2*x)*Dx + (x**2 + 6)*Dx**2 + (x**3 + 2*x)*Dx**3, \
129
+ x, 1, [sin(1) + 1, -1 + cos(1), -sin(1) + 2])
130
+ assert p + q == r
131
+ C_1 = symbols('C_1')
132
+ p = expr_to_holonomic(sqrt(x))
133
+ q = expr_to_holonomic(sqrt(x**2-x))
134
+ r = (p + q).to_expr().subs(C_1, -I/2).expand()
135
+ assert r == I*sqrt(x)*sqrt(-x + 1) + sqrt(x)
136
+
137
+
138
+ def test_multiplication_initial_condition():
139
+ x = symbols('x')
140
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
141
+ p = HolonomicFunction(Dx**2 + x*Dx - 1, x, 0, [3, 1])
142
+ q = HolonomicFunction(Dx**2 + 1, x, 0, [1, 1])
143
+ r = HolonomicFunction((x**4 + 14*x**2 + 60) + 4*x*Dx + (x**4 + 9*x**2 + 20)*Dx**2 + \
144
+ (2*x**3 + 18*x)*Dx**3 + (x**2 + 10)*Dx**4, x, 0, [3, 4, 2, 3])
145
+ assert p * q == r
146
+ p = HolonomicFunction(Dx**2 + x, x, 0, [1, 0])
147
+ q = HolonomicFunction(Dx**3 - x**2, x, 0, [3, 3, 3])
148
+ r = HolonomicFunction((x**8 - 37*x**7/27 - 10*x**6/27 - 164*x**5/9 - 184*x**4/9 + \
149
+ 160*x**3/27 + 404*x**2/9 + 8*x + Rational(40, 3)) + (6*x**7 - 128*x**6/9 - 98*x**5/9 - 28*x**4/9 + \
150
+ 8*x**3/9 + 28*x**2 + x*Rational(40, 9) - 40)*Dx + (3*x**6 - 82*x**5/9 + 76*x**4/9 + 4*x**3/3 + \
151
+ 220*x**2/9 - x*Rational(80, 3))*Dx**2 + (-2*x**6 + 128*x**5/27 - 2*x**4/3 -80*x**2/9 + Rational(200, 9))*Dx**3 + \
152
+ (3*x**5 - 64*x**4/9 - 28*x**3/9 + 6*x**2 - x*Rational(20, 9) - Rational(20, 3))*Dx**4 + (-4*x**3 + 64*x**2/9 + \
153
+ x*Rational(8, 3))*Dx**5 + (x**4 - 64*x**3/27 - 4*x**2/3 + Rational(20, 9))*Dx**6, x, 0, [3, 3, 3, -3, -12, -24])
154
+ assert p * q == r
155
+ p = HolonomicFunction(Dx - 1, x, 0, [2])
156
+ q = HolonomicFunction(Dx**2 + 1, x, 0, [0, 1])
157
+ r = HolonomicFunction(2 -2*Dx + Dx**2, x, 0, [0, 2])
158
+ assert p * q == r
159
+ q = HolonomicFunction(x*Dx**2 + 1 + 2*Dx, x, 0,[0, 1])
160
+ r = HolonomicFunction((x - 1) + (-2*x + 2)*Dx + x*Dx**2, x, 0, [0, 2])
161
+ assert p * q == r
162
+ p = HolonomicFunction(Dx**2 - 1, x, 0, [1, 3])
163
+ q = HolonomicFunction(Dx**3 + 1, x, 0, [1, 2, 1])
164
+ r = HolonomicFunction(6*Dx + 3*Dx**2 + 2*Dx**3 - 3*Dx**4 + Dx**6, x, 0, [1, 5, 14, 17, 17, 2])
165
+ assert p * q == r
166
+ p = expr_to_holonomic(sin(x))
167
+ q = expr_to_holonomic(1/x, x0=1)
168
+ r = HolonomicFunction(x + 2*Dx + x*Dx**2, x, 1, [sin(1), -sin(1) + cos(1)])
169
+ assert p * q == r
170
+ p = expr_to_holonomic(sqrt(x))
171
+ q = expr_to_holonomic(sqrt(x**2-x))
172
+ r = (p * q).to_expr()
173
+ assert r == I*x*sqrt(-x + 1)
174
+
175
+
176
+ def test_HolonomicFunction_composition():
177
+ x = symbols('x')
178
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
179
+ p = HolonomicFunction(Dx-1, x).composition(x**2+x)
180
+ r = HolonomicFunction((-2*x - 1) + Dx, x)
181
+ assert p == r
182
+ p = HolonomicFunction(Dx**2+1, x).composition(x**5+x**2+1)
183
+ r = HolonomicFunction((125*x**12 + 150*x**9 + 60*x**6 + 8*x**3) + (-20*x**3 - 2)*Dx + \
184
+ (5*x**4 + 2*x)*Dx**2, x)
185
+ assert p == r
186
+ p = HolonomicFunction(Dx**2*x+x, x).composition(2*x**3+x**2+1)
187
+ r = HolonomicFunction((216*x**9 + 324*x**8 + 180*x**7 + 152*x**6 + 112*x**5 + \
188
+ 36*x**4 + 4*x**3) + (24*x**4 + 16*x**3 + 3*x**2 - 6*x - 1)*Dx + (6*x**5 + 5*x**4 + \
189
+ x**3 + 3*x**2 + x)*Dx**2, x)
190
+ assert p == r
191
+ p = HolonomicFunction(Dx**2+1, x).composition(1-x**2)
192
+ r = HolonomicFunction((4*x**3) - Dx + x*Dx**2, x)
193
+ assert p == r
194
+ p = HolonomicFunction(Dx**2+1, x).composition(x - 2/(x**2 + 1))
195
+ r = HolonomicFunction((x**12 + 6*x**10 + 12*x**9 + 15*x**8 + 48*x**7 + 68*x**6 + \
196
+ 72*x**5 + 111*x**4 + 112*x**3 + 54*x**2 + 12*x + 1) + (12*x**8 + 32*x**6 + \
197
+ 24*x**4 - 4)*Dx + (x**12 + 6*x**10 + 4*x**9 + 15*x**8 + 16*x**7 + 20*x**6 + 24*x**5+ \
198
+ 15*x**4 + 16*x**3 + 6*x**2 + 4*x + 1)*Dx**2, x)
199
+ assert p == r
200
+
201
+
202
+ def test_from_hyper():
203
+ x = symbols('x')
204
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
205
+ p = hyper([1, 1], [Rational(3, 2)], x**2/4)
206
+ q = HolonomicFunction((4*x) + (5*x**2 - 8)*Dx + (x**3 - 4*x)*Dx**2, x, 1, [2*sqrt(3)*pi/9, -4*sqrt(3)*pi/27 + Rational(4, 3)])
207
+ r = from_hyper(p)
208
+ assert r == q
209
+ p = from_hyper(hyper([1], [Rational(3, 2)], x**2/4))
210
+ q = HolonomicFunction(-x + (-x**2/2 + 2)*Dx + x*Dx**2, x)
211
+ # x0 = 1
212
+ y0 = '[sqrt(pi)*exp(1/4)*erf(1/2), -sqrt(pi)*exp(1/4)*erf(1/2)/2 + 1]'
213
+ assert sstr(p.y0) == y0
214
+ assert q.annihilator == p.annihilator
215
+
216
+
217
+ def test_from_meijerg():
218
+ x = symbols('x')
219
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
220
+ p = from_meijerg(meijerg(([], [Rational(3, 2)]), ([S.Half], [S.Half, 1]), x))
221
+ q = HolonomicFunction(x/2 - Rational(1, 4) + (-x**2 + x/4)*Dx + x**2*Dx**2 + x**3*Dx**3, x, 1, \
222
+ [1/sqrt(pi), 1/(2*sqrt(pi)), -1/(4*sqrt(pi))])
223
+ assert p == q
224
+ p = from_meijerg(meijerg(([], []), ([0], []), x))
225
+ q = HolonomicFunction(1 + Dx, x, 0, [1])
226
+ assert p == q
227
+ p = from_meijerg(meijerg(([1], []), ([S.Half], [0]), x))
228
+ q = HolonomicFunction((x + S.Half)*Dx + x*Dx**2, x, 1, [sqrt(pi)*erf(1), exp(-1)])
229
+ assert p == q
230
+ p = from_meijerg(meijerg(([0], [1]), ([0], []), 2*x**2))
231
+ q = HolonomicFunction((3*x**2 - 1)*Dx + x**3*Dx**2, x, 1, [-exp(Rational(-1, 2)) + 1, -exp(Rational(-1, 2))])
232
+ assert p == q
233
+
234
+
235
+ def test_to_Sequence():
236
+ x = symbols('x')
237
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
238
+ n = symbols('n', integer=True)
239
+ _, Sn = RecurrenceOperators(ZZ.old_poly_ring(n), 'Sn')
240
+ p = HolonomicFunction(x**2*Dx**4 + x + Dx, x).to_sequence()
241
+ q = [(HolonomicSequence(1 + (n + 2)*Sn**2 + (n**4 + 6*n**3 + 11*n**2 + 6*n)*Sn**3), 0, 1)]
242
+ assert p == q
243
+ p = HolonomicFunction(x**2*Dx**4 + x**3 + Dx**2, x).to_sequence()
244
+ q = [(HolonomicSequence(1 + (n**4 + 14*n**3 + 72*n**2 + 163*n + 140)*Sn**5), 0, 0)]
245
+ assert p == q
246
+ p = HolonomicFunction(x**3*Dx**4 + 1 + Dx**2, x).to_sequence()
247
+ q = [(HolonomicSequence(1 + (n**4 - 2*n**3 - n**2 + 2*n)*Sn + (n**2 + 3*n + 2)*Sn**2), 0, 0)]
248
+ assert p == q
249
+ p = HolonomicFunction(3*x**3*Dx**4 + 2*x*Dx + x*Dx**3, x).to_sequence()
250
+ q = [(HolonomicSequence(2*n + (3*n**4 - 6*n**3 - 3*n**2 + 6*n)*Sn + (n**3 + 3*n**2 + 2*n)*Sn**2), 0, 1)]
251
+ assert p == q
252
+
253
+
254
+ def test_to_Sequence_Initial_Coniditons():
255
+ x = symbols('x')
256
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
257
+ n = symbols('n', integer=True)
258
+ _, Sn = RecurrenceOperators(QQ.old_poly_ring(n), 'Sn')
259
+ p = HolonomicFunction(Dx - 1, x, 0, [1]).to_sequence()
260
+ q = [(HolonomicSequence(-1 + (n + 1)*Sn, 1), 0)]
261
+ assert p == q
262
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [0, 1]).to_sequence()
263
+ q = [(HolonomicSequence(1 + (n**2 + 3*n + 2)*Sn**2, [0, 1]), 0)]
264
+ assert p == q
265
+ p = HolonomicFunction(Dx**2 + 1 + x**3*Dx, x, 0, [2, 3]).to_sequence()
266
+ q = [(HolonomicSequence(n + Sn**2 + (n**2 + 7*n + 12)*Sn**4, [2, 3, -1, Rational(-1, 2), Rational(1, 12)]), 1)]
267
+ assert p == q
268
+ p = HolonomicFunction(x**3*Dx**5 + 1 + Dx, x).to_sequence()
269
+ q = [(HolonomicSequence(1 + (n + 1)*Sn + (n**5 - 5*n**3 + 4*n)*Sn**2), 0, 3)]
270
+ assert p == q
271
+ C_0, C_1, C_2, C_3 = symbols('C_0, C_1, C_2, C_3')
272
+ p = expr_to_holonomic(log(1+x**2))
273
+ q = [(HolonomicSequence(n**2 + (n**2 + 2*n)*Sn**2, [0, 0, C_2]), 0, 1)]
274
+ assert p.to_sequence() == q
275
+ p = p.diff()
276
+ q = [(HolonomicSequence((n + 2) + (n + 2)*Sn**2, [C_0, 0]), 1, 0)]
277
+ assert p.to_sequence() == q
278
+ p = expr_to_holonomic(erf(x) + x).to_sequence()
279
+ q = [(HolonomicSequence((2*n**2 - 2*n) + (n**3 + 2*n**2 - n - 2)*Sn**2, [0, 1 + 2/sqrt(pi), 0, C_3]), 0, 2)]
280
+ assert p == q
281
+
282
+ def test_series():
283
+ x = symbols('x')
284
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
285
+ p = HolonomicFunction(Dx**2 + 2*x*Dx, x, 0, [0, 1]).series(n=10)
286
+ q = x - x**3/3 + x**5/10 - x**7/42 + x**9/216 + O(x**10)
287
+ assert p == q
288
+ p = HolonomicFunction(Dx - 1, x).composition(x**2, 0, [1]) # e^(x**2)
289
+ q = HolonomicFunction(Dx**2 + 1, x, 0, [1, 0]) # cos(x)
290
+ r = (p * q).series(n=10) # expansion of cos(x) * exp(x**2)
291
+ s = 1 + x**2/2 + x**4/24 - 31*x**6/720 - 179*x**8/8064 + O(x**10)
292
+ assert r == s
293
+ t = HolonomicFunction((1 + x)*Dx**2 + Dx, x, 0, [0, 1]) # log(1 + x)
294
+ r = (p * t + q).series(n=10)
295
+ s = 1 + x - x**2 + 4*x**3/3 - 17*x**4/24 + 31*x**5/30 - 481*x**6/720 +\
296
+ 71*x**7/105 - 20159*x**8/40320 + 379*x**9/840 + O(x**10)
297
+ assert r == s
298
+ p = HolonomicFunction((6+6*x-3*x**2) - (10*x-3*x**2-3*x**3)*Dx + \
299
+ (4-6*x**3+2*x**4)*Dx**2, x, 0, [0, 1]).series(n=7)
300
+ q = x + x**3/6 - 3*x**4/16 + x**5/20 - 23*x**6/960 + O(x**7)
301
+ assert p == q
302
+ p = HolonomicFunction((6+6*x-3*x**2) - (10*x-3*x**2-3*x**3)*Dx + \
303
+ (4-6*x**3+2*x**4)*Dx**2, x, 0, [1, 0]).series(n=7)
304
+ q = 1 - 3*x**2/4 - x**3/4 - 5*x**4/32 - 3*x**5/40 - 17*x**6/384 + O(x**7)
305
+ assert p == q
306
+ p = expr_to_holonomic(erf(x) + x).series(n=10)
307
+ C_3 = symbols('C_3')
308
+ q = (erf(x) + x).series(n=10)
309
+ assert p.subs(C_3, -2/(3*sqrt(pi))) == q
310
+ assert expr_to_holonomic(sqrt(x**3 + x)).series(n=10) == sqrt(x**3 + x).series(n=10)
311
+ assert expr_to_holonomic((2*x - 3*x**2)**Rational(1, 3)).series() == ((2*x - 3*x**2)**Rational(1, 3)).series()
312
+ assert expr_to_holonomic(sqrt(x**2-x)).series() == (sqrt(x**2-x)).series()
313
+ assert expr_to_holonomic(cos(x)**2/x**2, y0={-2: [1, 0, -1]}).series(n=10) == (cos(x)**2/x**2).series(n=10)
314
+ assert expr_to_holonomic(cos(x)**2/x**2, x0=1).series(n=10).together() == (cos(x)**2/x**2).series(n=10, x0=1).together()
315
+ assert expr_to_holonomic(cos(x-1)**2/(x-1)**2, x0=1, y0={-2: [1, 0, -1]}).series(n=10) \
316
+ == (cos(x-1)**2/(x-1)**2).series(x0=1, n=10)
317
+
318
+ def test_evalf_euler():
319
+ x = symbols('x')
320
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
321
+
322
+ # log(1+x)
323
+ p = HolonomicFunction((1 + x)*Dx**2 + Dx, x, 0, [0, 1])
324
+
325
+ # path taken is a straight line from 0 to 1, on the real axis
326
+ r = [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1]
327
+ s = '0.699525841805253' # approx. equal to log(2) i.e. 0.693147180559945
328
+ assert sstr(p.evalf(r, method='Euler')[-1]) == s
329
+
330
+ # path taken is a triangle 0-->1+i-->2
331
+ r = [0.1 + 0.1*I]
332
+ for i in range(9):
333
+ r.append(r[-1]+0.1+0.1*I)
334
+ for i in range(10):
335
+ r.append(r[-1]+0.1-0.1*I)
336
+
337
+ # close to the exact solution 1.09861228866811
338
+ # imaginary part also close to zero
339
+ s = '1.07530466271334 - 0.0251200594793912*I'
340
+ assert sstr(p.evalf(r, method='Euler')[-1]) == s
341
+
342
+ # sin(x)
343
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [0, 1])
344
+ s = '0.905546532085401 - 6.93889390390723e-18*I'
345
+ assert sstr(p.evalf(r, method='Euler')[-1]) == s
346
+
347
+ # computing sin(pi/2) using this method
348
+ # using a linear path from 0 to pi/2
349
+ r = [0.1]
350
+ for i in range(14):
351
+ r.append(r[-1] + 0.1)
352
+ r.append(pi/2)
353
+ s = '1.08016557252834' # close to 1.0 (exact solution)
354
+ assert sstr(p.evalf(r, method='Euler')[-1]) == s
355
+
356
+ # trying different path, a rectangle (0-->i-->pi/2 + i-->pi/2)
357
+ # computing the same value sin(pi/2) using different path
358
+ r = [0.1*I]
359
+ for i in range(9):
360
+ r.append(r[-1]+0.1*I)
361
+ for i in range(15):
362
+ r.append(r[-1]+0.1)
363
+ r.append(pi/2+I)
364
+ for i in range(10):
365
+ r.append(r[-1]-0.1*I)
366
+
367
+ # close to 1.0
368
+ s = '0.976882381836257 - 1.65557671738537e-16*I'
369
+ assert sstr(p.evalf(r, method='Euler')[-1]) == s
370
+
371
+ # cos(x)
372
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [1, 0])
373
+ # compute cos(pi) along 0-->pi
374
+ r = [0.05]
375
+ for i in range(61):
376
+ r.append(r[-1]+0.05)
377
+ r.append(pi)
378
+ # close to -1 (exact answer)
379
+ s = '-1.08140824719196'
380
+ assert sstr(p.evalf(r, method='Euler')[-1]) == s
381
+
382
+ # a rectangular path (0 -> i -> 2+i -> 2)
383
+ r = [0.1*I]
384
+ for i in range(9):
385
+ r.append(r[-1]+0.1*I)
386
+ for i in range(20):
387
+ r.append(r[-1]+0.1)
388
+ for i in range(10):
389
+ r.append(r[-1]-0.1*I)
390
+
391
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [1,1]).evalf(r, method='Euler')
392
+ s = '0.501421652861245 - 3.88578058618805e-16*I'
393
+ assert sstr(p[-1]) == s
394
+
395
+ def test_evalf_rk4():
396
+ x = symbols('x')
397
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
398
+
399
+ # log(1+x)
400
+ p = HolonomicFunction((1 + x)*Dx**2 + Dx, x, 0, [0, 1])
401
+
402
+ # path taken is a straight line from 0 to 1, on the real axis
403
+ r = [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1]
404
+ s = '0.693146363174626' # approx. equal to log(2) i.e. 0.693147180559945
405
+ assert sstr(p.evalf(r)[-1]) == s
406
+
407
+ # path taken is a triangle 0-->1+i-->2
408
+ r = [0.1 + 0.1*I]
409
+ for i in range(9):
410
+ r.append(r[-1]+0.1+0.1*I)
411
+ for i in range(10):
412
+ r.append(r[-1]+0.1-0.1*I)
413
+
414
+ # close to the exact solution 1.09861228866811
415
+ # imaginary part also close to zero
416
+ s = '1.098616 + 1.36083e-7*I'
417
+ assert sstr(p.evalf(r)[-1].n(7)) == s
418
+
419
+ # sin(x)
420
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [0, 1])
421
+ s = '0.90929463522785 + 1.52655665885959e-16*I'
422
+ assert sstr(p.evalf(r)[-1]) == s
423
+
424
+ # computing sin(pi/2) using this method
425
+ # using a linear path from 0 to pi/2
426
+ r = [0.1]
427
+ for i in range(14):
428
+ r.append(r[-1] + 0.1)
429
+ r.append(pi/2)
430
+ s = '0.999999895088917' # close to 1.0 (exact solution)
431
+ assert sstr(p.evalf(r)[-1]) == s
432
+
433
+ # trying different path, a rectangle (0-->i-->pi/2 + i-->pi/2)
434
+ # computing the same value sin(pi/2) using different path
435
+ r = [0.1*I]
436
+ for i in range(9):
437
+ r.append(r[-1]+0.1*I)
438
+ for i in range(15):
439
+ r.append(r[-1]+0.1)
440
+ r.append(pi/2+I)
441
+ for i in range(10):
442
+ r.append(r[-1]-0.1*I)
443
+
444
+ # close to 1.0
445
+ s = '1.00000003415141 + 6.11940487991086e-16*I'
446
+ assert sstr(p.evalf(r)[-1]) == s
447
+
448
+ # cos(x)
449
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [1, 0])
450
+ # compute cos(pi) along 0-->pi
451
+ r = [0.05]
452
+ for i in range(61):
453
+ r.append(r[-1]+0.05)
454
+ r.append(pi)
455
+ # close to -1 (exact answer)
456
+ s = '-0.999999993238714'
457
+ assert sstr(p.evalf(r)[-1]) == s
458
+
459
+ # a rectangular path (0 -> i -> 2+i -> 2)
460
+ r = [0.1*I]
461
+ for i in range(9):
462
+ r.append(r[-1]+0.1*I)
463
+ for i in range(20):
464
+ r.append(r[-1]+0.1)
465
+ for i in range(10):
466
+ r.append(r[-1]-0.1*I)
467
+
468
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [1,1]).evalf(r)
469
+ s = '0.493152791638442 - 1.41553435639707e-15*I'
470
+ assert sstr(p[-1]) == s
471
+
472
+
473
+ def test_expr_to_holonomic():
474
+ x = symbols('x')
475
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
476
+ p = expr_to_holonomic((sin(x)/x)**2)
477
+ q = HolonomicFunction(8*x + (4*x**2 + 6)*Dx + 6*x*Dx**2 + x**2*Dx**3, x, 0, \
478
+ [1, 0, Rational(-2, 3)])
479
+ assert p == q
480
+ p = expr_to_holonomic(1/(1+x**2)**2)
481
+ q = HolonomicFunction(4*x + (x**2 + 1)*Dx, x, 0, [1])
482
+ assert p == q
483
+ p = expr_to_holonomic(exp(x)*sin(x)+x*log(1+x))
484
+ q = HolonomicFunction((2*x**3 + 10*x**2 + 20*x + 18) + (-2*x**4 - 10*x**3 - 20*x**2 \
485
+ - 18*x)*Dx + (2*x**5 + 6*x**4 + 7*x**3 + 8*x**2 + 10*x - 4)*Dx**2 + \
486
+ (-2*x**5 - 5*x**4 - 2*x**3 + 2*x**2 - x + 4)*Dx**3 + (x**5 + 2*x**4 - x**3 - \
487
+ 7*x**2/2 + x + Rational(5, 2))*Dx**4, x, 0, [0, 1, 4, -1])
488
+ assert p == q
489
+ p = expr_to_holonomic(x*exp(x)+cos(x)+1)
490
+ q = HolonomicFunction((-x - 3)*Dx + (x + 2)*Dx**2 + (-x - 3)*Dx**3 + (x + 2)*Dx**4, x, \
491
+ 0, [2, 1, 1, 3])
492
+ assert p == q
493
+ assert (x*exp(x)+cos(x)+1).series(n=10) == p.series(n=10)
494
+ p = expr_to_holonomic(log(1 + x)**2 + 1)
495
+ q = HolonomicFunction(Dx + (3*x + 3)*Dx**2 + (x**2 + 2*x + 1)*Dx**3, x, 0, [1, 0, 2])
496
+ assert p == q
497
+ p = expr_to_holonomic(erf(x)**2 + x)
498
+ q = HolonomicFunction((8*x**4 - 2*x**2 + 2)*Dx**2 + (6*x**3 - x/2)*Dx**3 + \
499
+ (x**2+ Rational(1, 4))*Dx**4, x, 0, [0, 1, 8/pi, 0])
500
+ assert p == q
501
+ p = expr_to_holonomic(cosh(x)*x)
502
+ q = HolonomicFunction((-x**2 + 2) -2*x*Dx + x**2*Dx**2, x, 0, [0, 1])
503
+ assert p == q
504
+ p = expr_to_holonomic(besselj(2, x))
505
+ q = HolonomicFunction((x**2 - 4) + x*Dx + x**2*Dx**2, x, 0, [0, 0])
506
+ assert p == q
507
+ p = expr_to_holonomic(besselj(0, x) + exp(x))
508
+ q = HolonomicFunction((-x**2 - x/2 + S.Half) + (x**2 - x/2 - Rational(3, 2))*Dx + (-x**2 + x/2 + 1)*Dx**2 +\
509
+ (x**2 + x/2)*Dx**3, x, 0, [2, 1, S.Half])
510
+ assert p == q
511
+ p = expr_to_holonomic(sin(x)**2/x)
512
+ q = HolonomicFunction(4 + 4*x*Dx + 3*Dx**2 + x*Dx**3, x, 0, [0, 1, 0])
513
+ assert p == q
514
+ p = expr_to_holonomic(sin(x)**2/x, x0=2)
515
+ q = HolonomicFunction((4) + (4*x)*Dx + (3)*Dx**2 + (x)*Dx**3, x, 2, [sin(2)**2/2,
516
+ sin(2)*cos(2) - sin(2)**2/4, -3*sin(2)**2/4 + cos(2)**2 - sin(2)*cos(2)])
517
+ assert p == q
518
+ p = expr_to_holonomic(log(x)/2 - Ci(2*x)/2 + Ci(2)/2)
519
+ q = HolonomicFunction(4*Dx + 4*x*Dx**2 + 3*Dx**3 + x*Dx**4, x, 0, \
520
+ [-log(2)/2 - EulerGamma/2 + Ci(2)/2, 0, 1, 0])
521
+ assert p == q
522
+ p = p.to_expr()
523
+ q = log(x)/2 - Ci(2*x)/2 + Ci(2)/2
524
+ assert p == q
525
+ p = expr_to_holonomic(x**S.Half, x0=1)
526
+ q = HolonomicFunction(x*Dx - S.Half, x, 1, [1])
527
+ assert p == q
528
+ p = expr_to_holonomic(sqrt(1 + x**2))
529
+ q = HolonomicFunction((-x) + (x**2 + 1)*Dx, x, 0, [1])
530
+ assert p == q
531
+ assert (expr_to_holonomic(sqrt(x) + sqrt(2*x)).to_expr()-\
532
+ (sqrt(x) + sqrt(2*x))).simplify() == 0
533
+ assert expr_to_holonomic(3*x+2*sqrt(x)).to_expr() == 3*x+2*sqrt(x)
534
+ p = expr_to_holonomic((x**4+x**3+5*x**2+3*x+2)/x**2, lenics=3)
535
+ q = HolonomicFunction((-2*x**4 - x**3 + 3*x + 4) + (x**5 + x**4 + 5*x**3 + 3*x**2 + \
536
+ 2*x)*Dx, x, 0, {-2: [2, 3, 5]})
537
+ assert p == q
538
+ p = expr_to_holonomic(1/(x-1)**2, lenics=3, x0=1)
539
+ q = HolonomicFunction((2) + (x - 1)*Dx, x, 1, {-2: [1, 0, 0]})
540
+ assert p == q
541
+ a = symbols("a")
542
+ p = expr_to_holonomic(sqrt(a*x), x=x)
543
+ assert p.to_expr() == sqrt(a)*sqrt(x)
544
+
545
+ def test_to_hyper():
546
+ x = symbols('x')
547
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
548
+ p = HolonomicFunction(Dx - 2, x, 0, [3]).to_hyper()
549
+ q = 3 * hyper([], [], 2*x)
550
+ assert p == q
551
+ p = hyperexpand(HolonomicFunction((1 + x) * Dx - 3, x, 0, [2]).to_hyper()).expand()
552
+ q = 2*x**3 + 6*x**2 + 6*x + 2
553
+ assert p == q
554
+ p = HolonomicFunction((1 + x)*Dx**2 + Dx, x, 0, [0, 1]).to_hyper()
555
+ q = -x**2*hyper((2, 2, 1), (3, 2), -x)/2 + x
556
+ assert p == q
557
+ p = HolonomicFunction(2*x*Dx + Dx**2, x, 0, [0, 2/sqrt(pi)]).to_hyper()
558
+ q = 2*x*hyper((S.Half,), (Rational(3, 2),), -x**2)/sqrt(pi)
559
+ assert p == q
560
+ p = hyperexpand(HolonomicFunction(2*x*Dx + Dx**2, x, 0, [1, -2/sqrt(pi)]).to_hyper())
561
+ q = erfc(x)
562
+ assert p.rewrite(erfc) == q
563
+ p = hyperexpand(HolonomicFunction((x**2 - 1) + x*Dx + x**2*Dx**2,
564
+ x, 0, [0, S.Half]).to_hyper())
565
+ q = besselj(1, x)
566
+ assert p == q
567
+ p = hyperexpand(HolonomicFunction(x*Dx**2 + Dx + x, x, 0, [1, 0]).to_hyper())
568
+ q = besselj(0, x)
569
+ assert p == q
570
+
571
+ def test_to_expr():
572
+ x = symbols('x')
573
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
574
+ p = HolonomicFunction(Dx - 1, x, 0, [1]).to_expr()
575
+ q = exp(x)
576
+ assert p == q
577
+ p = HolonomicFunction(Dx**2 + 1, x, 0, [1, 0]).to_expr()
578
+ q = cos(x)
579
+ assert p == q
580
+ p = HolonomicFunction(Dx**2 - 1, x, 0, [1, 0]).to_expr()
581
+ q = cosh(x)
582
+ assert p == q
583
+ p = HolonomicFunction(2 + (4*x - 1)*Dx + \
584
+ (x**2 - x)*Dx**2, x, 0, [1, 2]).to_expr().expand()
585
+ q = 1/(x**2 - 2*x + 1)
586
+ assert p == q
587
+ p = expr_to_holonomic(sin(x)**2/x).integrate((x, 0, x)).to_expr()
588
+ q = (sin(x)**2/x).integrate((x, 0, x))
589
+ assert p == q
590
+ C_0, C_1, C_2, C_3 = symbols('C_0, C_1, C_2, C_3')
591
+ p = expr_to_holonomic(log(1+x**2)).to_expr()
592
+ q = C_2*log(x**2 + 1)
593
+ assert p == q
594
+ p = expr_to_holonomic(log(1+x**2)).diff().to_expr()
595
+ q = C_0*x/(x**2 + 1)
596
+ assert p == q
597
+ p = expr_to_holonomic(erf(x) + x).to_expr()
598
+ q = 3*C_3*x - 3*sqrt(pi)*C_3*erf(x)/2 + x + 2*x/sqrt(pi)
599
+ assert p == q
600
+ p = expr_to_holonomic(sqrt(x), x0=1).to_expr()
601
+ assert p == sqrt(x)
602
+ assert expr_to_holonomic(sqrt(x)).to_expr() == sqrt(x)
603
+ p = expr_to_holonomic(sqrt(1 + x**2)).to_expr()
604
+ assert p == sqrt(1+x**2)
605
+ p = expr_to_holonomic((2*x**2 + 1)**Rational(2, 3)).to_expr()
606
+ assert p == (2*x**2 + 1)**Rational(2, 3)
607
+ p = expr_to_holonomic(sqrt(-x**2+2*x)).to_expr()
608
+ assert p == sqrt(x)*sqrt(-x + 2)
609
+ p = expr_to_holonomic((-2*x**3+7*x)**Rational(2, 3)).to_expr()
610
+ q = x**Rational(2, 3)*(-2*x**2 + 7)**Rational(2, 3)
611
+ assert p == q
612
+ p = from_hyper(hyper((-2, -3), (S.Half, ), x))
613
+ s = hyperexpand(hyper((-2, -3), (S.Half, ), x))
614
+ D_0 = Symbol('D_0')
615
+ C_0 = Symbol('C_0')
616
+ assert (p.to_expr().subs({C_0:1, D_0:0}) - s).simplify() == 0
617
+ p.y0 = {0: [1], S.Half: [0]}
618
+ assert p.to_expr() == s
619
+ assert expr_to_holonomic(x**5).to_expr() == x**5
620
+ assert expr_to_holonomic(2*x**3-3*x**2).to_expr().expand() == \
621
+ 2*x**3-3*x**2
622
+ a = symbols("a")
623
+ p = (expr_to_holonomic(1.4*x)*expr_to_holonomic(a*x, x)).to_expr()
624
+ q = 1.4*a*x**2
625
+ assert p == q
626
+ p = (expr_to_holonomic(1.4*x)+expr_to_holonomic(a*x, x)).to_expr()
627
+ q = x*(a + 1.4)
628
+ assert p == q
629
+ p = (expr_to_holonomic(1.4*x)+expr_to_holonomic(x)).to_expr()
630
+ assert p == 2.4*x
631
+
632
+
633
+ def test_integrate():
634
+ x = symbols('x')
635
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
636
+ p = expr_to_holonomic(sin(x)**2/x, x0=1).integrate((x, 2, 3))
637
+ q = '0.166270406994788'
638
+ assert sstr(p) == q
639
+ p = expr_to_holonomic(sin(x)).integrate((x, 0, x)).to_expr()
640
+ q = 1 - cos(x)
641
+ assert p == q
642
+ p = expr_to_holonomic(sin(x)).integrate((x, 0, 3))
643
+ q = 1 - cos(3)
644
+ assert p == q
645
+ p = expr_to_holonomic(sin(x)/x, x0=1).integrate((x, 1, 2))
646
+ q = '0.659329913368450'
647
+ assert sstr(p) == q
648
+ p = expr_to_holonomic(sin(x)**2/x, x0=1).integrate((x, 1, 0))
649
+ q = '-0.423690480850035'
650
+ assert sstr(p) == q
651
+ p = expr_to_holonomic(sin(x)/x)
652
+ assert p.integrate(x).to_expr() == Si(x)
653
+ assert p.integrate((x, 0, 2)) == Si(2)
654
+ p = expr_to_holonomic(sin(x)**2/x)
655
+ q = p.to_expr()
656
+ assert p.integrate(x).to_expr() == q.integrate((x, 0, x))
657
+ assert p.integrate((x, 0, 1)) == q.integrate((x, 0, 1))
658
+ assert expr_to_holonomic(1/x, x0=1).integrate(x).to_expr() == log(x)
659
+ p = expr_to_holonomic((x + 1)**3*exp(-x), x0=-1).integrate(x).to_expr()
660
+ q = (-x**3 - 6*x**2 - 15*x + 6*exp(x + 1) - 16)*exp(-x)
661
+ assert p == q
662
+ p = expr_to_holonomic(cos(x)**2/x**2, y0={-2: [1, 0, -1]}).integrate(x).to_expr()
663
+ q = -Si(2*x) - cos(x)**2/x
664
+ assert p == q
665
+ p = expr_to_holonomic(sqrt(x**2+x)).integrate(x).to_expr()
666
+ q = (x**Rational(3, 2)*(2*x**2 + 3*x + 1) - x*sqrt(x + 1)*asinh(sqrt(x)))/(4*x*sqrt(x + 1))
667
+ assert p == q
668
+ p = expr_to_holonomic(sqrt(x**2+1)).integrate(x).to_expr()
669
+ q = (sqrt(x**2+1)).integrate(x)
670
+ assert (p-q).simplify() == 0
671
+ p = expr_to_holonomic(1/x**2, y0={-2:[1, 0, 0]})
672
+ r = expr_to_holonomic(1/x**2, lenics=3)
673
+ assert p == r
674
+ q = expr_to_holonomic(cos(x)**2)
675
+ assert (r*q).integrate(x).to_expr() == -Si(2*x) - cos(x)**2/x
676
+
677
+
678
+ def test_diff():
679
+ x, y = symbols('x, y')
680
+ R, Dx = DifferentialOperators(ZZ.old_poly_ring(x), 'Dx')
681
+ p = HolonomicFunction(x*Dx**2 + 1, x, 0, [0, 1])
682
+ assert p.diff().to_expr() == p.to_expr().diff().simplify()
683
+ p = HolonomicFunction(Dx**2 - 1, x, 0, [1, 0])
684
+ assert p.diff(x, 2).to_expr() == p.to_expr()
685
+ p = expr_to_holonomic(Si(x))
686
+ assert p.diff().to_expr() == sin(x)/x
687
+ assert p.diff(y) == 0
688
+ C_0, C_1, C_2, C_3 = symbols('C_0, C_1, C_2, C_3')
689
+ q = Si(x)
690
+ assert p.diff(x).to_expr() == q.diff()
691
+ assert p.diff(x, 2).to_expr().subs(C_0, Rational(-1, 3)).cancel() == q.diff(x, 2).cancel()
692
+ assert p.diff(x, 3).series().subs({C_3: Rational(-1, 3), C_0: 0}) == q.diff(x, 3).series()
693
+
694
+
695
+ def test_extended_domain_in_expr_to_holonomic():
696
+ x = symbols('x')
697
+ p = expr_to_holonomic(1.2*cos(3.1*x))
698
+ assert p.to_expr() == 1.2*cos(3.1*x)
699
+ assert sstr(p.integrate(x).to_expr()) == '0.387096774193548*sin(3.1*x)'
700
+ _, Dx = DifferentialOperators(RR.old_poly_ring(x), 'Dx')
701
+ p = expr_to_holonomic(1.1329138213*x)
702
+ q = HolonomicFunction((-1.1329138213) + (1.1329138213*x)*Dx, x, 0, {1: [1.1329138213]})
703
+ assert p == q
704
+ assert p.to_expr() == 1.1329138213*x
705
+ assert sstr(p.integrate((x, 1, 2))) == sstr((1.1329138213*x).integrate((x, 1, 2)))
706
+ y, z = symbols('y, z')
707
+ p = expr_to_holonomic(sin(x*y*z), x=x)
708
+ assert p.to_expr() == sin(x*y*z)
709
+ assert p.integrate(x).to_expr() == (-cos(x*y*z) + 1)/(y*z)
710
+ p = expr_to_holonomic(sin(x*y + z), x=x).integrate(x).to_expr()
711
+ q = (cos(z) - cos(x*y + z))/y
712
+ assert p == q
713
+ a = symbols('a')
714
+ p = expr_to_holonomic(a*x, x)
715
+ assert p.to_expr() == a*x
716
+ assert p.integrate(x).to_expr() == a*x**2/2
717
+ D_2, C_1 = symbols("D_2, C_1")
718
+ p = expr_to_holonomic(x) + expr_to_holonomic(1.2*cos(x))
719
+ p = p.to_expr().subs(D_2, 0)
720
+ assert p - x - 1.2*cos(1.0*x) == 0
721
+ p = expr_to_holonomic(x) * expr_to_holonomic(1.2*cos(x))
722
+ p = p.to_expr().subs(C_1, 0)
723
+ assert p - 1.2*x*cos(1.0*x) == 0
724
+
725
+
726
+ def test_to_meijerg():
727
+ x = symbols('x')
728
+ assert hyperexpand(expr_to_holonomic(sin(x)).to_meijerg()) == sin(x)
729
+ assert hyperexpand(expr_to_holonomic(cos(x)).to_meijerg()) == cos(x)
730
+ assert hyperexpand(expr_to_holonomic(exp(x)).to_meijerg()) == exp(x)
731
+ assert hyperexpand(expr_to_holonomic(log(x)).to_meijerg()).simplify() == log(x)
732
+ assert expr_to_holonomic(4*x**2/3 + 7).to_meijerg() == 4*x**2/3 + 7
733
+ assert hyperexpand(expr_to_holonomic(besselj(2, x), lenics=3).to_meijerg()) == besselj(2, x)
734
+ p = hyper((Rational(-1, 2), -3), (), x)
735
+ assert from_hyper(p).to_meijerg() == hyperexpand(p)
736
+ p = hyper((S.One, S(3)), (S(2), ), x)
737
+ assert (hyperexpand(from_hyper(p).to_meijerg()) - hyperexpand(p)).expand() == 0
738
+ p = from_hyper(hyper((-2, -3), (S.Half, ), x))
739
+ s = hyperexpand(hyper((-2, -3), (S.Half, ), x))
740
+ C_0 = Symbol('C_0')
741
+ C_1 = Symbol('C_1')
742
+ D_0 = Symbol('D_0')
743
+ assert (hyperexpand(p.to_meijerg()).subs({C_0:1, D_0:0}) - s).simplify() == 0
744
+ p.y0 = {0: [1], S.Half: [0]}
745
+ assert (hyperexpand(p.to_meijerg()) - s).simplify() == 0
746
+ p = expr_to_holonomic(besselj(S.Half, x), initcond=False)
747
+ assert (p.to_expr() - (D_0*sin(x) + C_0*cos(x) + C_1*sin(x))/sqrt(x)).simplify() == 0
748
+ p = expr_to_holonomic(besselj(S.Half, x), y0={Rational(-1, 2): [sqrt(2)/sqrt(pi), sqrt(2)/sqrt(pi)]})
749
+ assert (p.to_expr() - besselj(S.Half, x) - besselj(Rational(-1, 2), x)).simplify() == 0
750
+
751
+
752
+ def test_gaussian():
753
+ mu, x = symbols("mu x")
754
+ sd = symbols("sd", positive=True)
755
+ Q = QQ[mu, sd].get_field()
756
+ e = sqrt(2)*exp(-(-mu + x)**2/(2*sd**2))/(2*sqrt(pi)*sd)
757
+ h1 = expr_to_holonomic(e, x, domain=Q)
758
+
759
+ _, Dx = DifferentialOperators(Q.old_poly_ring(x), 'Dx')
760
+ h2 = HolonomicFunction((-mu/sd**2 + x/sd**2) + (1)*Dx, x)
761
+
762
+ assert h1 == h2
763
+
764
+
765
+ def test_beta():
766
+ a, b, x = symbols("a b x", positive=True)
767
+ e = x**(a - 1)*(-x + 1)**(b - 1)/beta(a, b)
768
+ Q = QQ[a, b].get_field()
769
+ h1 = expr_to_holonomic(e, x, domain=Q)
770
+
771
+ _, Dx = DifferentialOperators(Q.old_poly_ring(x), 'Dx')
772
+ h2 = HolonomicFunction((a + x*(-a - b + 2) - 1) + (x**2 - x)*Dx, x)
773
+
774
+ assert h1 == h2
775
+
776
+
777
+ def test_gamma():
778
+ a, b, x = symbols("a b x", positive=True)
779
+ e = b**(-a)*x**(a - 1)*exp(-x/b)/gamma(a)
780
+ Q = QQ[a, b].get_field()
781
+ h1 = expr_to_holonomic(e, x, domain=Q)
782
+
783
+ _, Dx = DifferentialOperators(Q.old_poly_ring(x), 'Dx')
784
+ h2 = HolonomicFunction((-a + 1 + x/b) + (x)*Dx, x)
785
+
786
+ assert h1 == h2
787
+
788
+
789
+ def test_symbolic_power():
790
+ x, n = symbols("x n")
791
+ Q = QQ[n].get_field()
792
+ _, Dx = DifferentialOperators(Q.old_poly_ring(x), 'Dx')
793
+ h1 = HolonomicFunction((-1) + (x)*Dx, x) ** -n
794
+ h2 = HolonomicFunction((n) + (x)*Dx, x)
795
+
796
+ assert h1 == h2
797
+
798
+
799
+ def test_negative_power():
800
+ x = symbols("x")
801
+ _, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
802
+ h1 = HolonomicFunction((-1) + (x)*Dx, x) ** -2
803
+ h2 = HolonomicFunction((2) + (x)*Dx, x)
804
+
805
+ assert h1 == h2
806
+
807
+
808
+ def test_expr_in_power():
809
+ x, n = symbols("x n")
810
+ Q = QQ[n].get_field()
811
+ _, Dx = DifferentialOperators(Q.old_poly_ring(x), 'Dx')
812
+ h1 = HolonomicFunction((-1) + (x)*Dx, x) ** (n - 3)
813
+ h2 = HolonomicFunction((-n + 3) + (x)*Dx, x)
814
+
815
+ assert h1 == h2
816
+
817
+ def test_DifferentialOperatorEqPoly():
818
+ x = symbols('x', integer=True)
819
+ R, Dx = DifferentialOperators(QQ.old_poly_ring(x), 'Dx')
820
+ do = DifferentialOperator([x**2, R.base.zero, R.base.zero], R)
821
+ do2 = DifferentialOperator([x**2, 1, x], R)
822
+ assert not do == do2
823
+
824
+ # polynomial comparison issue, see https://github.com/sympy/sympy/pull/15799
825
+ # should work once that is solved
826
+ # p = do.listofpoly[0]
827
+ # assert do == p
828
+
829
+ p2 = do2.listofpoly[0]
830
+ assert not do2 == p2
llmeval-env/lib/python3.10/site-packages/sympy/holonomic/tests/test_recurrence.py ADDED
@@ -0,0 +1,29 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.holonomic.recurrence import RecurrenceOperators, RecurrenceOperator
2
+ from sympy.core.symbol import symbols
3
+ from sympy.polys.domains.rationalfield import QQ
4
+
5
+ def test_RecurrenceOperator():
6
+ n = symbols('n', integer=True)
7
+ R, Sn = RecurrenceOperators(QQ.old_poly_ring(n), 'Sn')
8
+ assert Sn*n == (n + 1)*Sn
9
+ assert Sn*n**2 == (n**2+1+2*n)*Sn
10
+ assert Sn**2*n**2 == (n**2 + 4*n + 4)*Sn**2
11
+ p = (Sn**3*n**2 + Sn*n)**2
12
+ q = (n**2 + 3*n + 2)*Sn**2 + (2*n**3 + 19*n**2 + 57*n + 52)*Sn**4 + (n**4 + 18*n**3 + \
13
+ 117*n**2 + 324*n + 324)*Sn**6
14
+ assert p == q
15
+
16
+ def test_RecurrenceOperatorEqPoly():
17
+ n = symbols('n', integer=True)
18
+ R, Sn = RecurrenceOperators(QQ.old_poly_ring(n), 'Sn')
19
+ rr = RecurrenceOperator([n**2, 0, 0], R)
20
+ rr2 = RecurrenceOperator([n**2, 1, n], R)
21
+ assert not rr == rr2
22
+
23
+ # polynomial comparison issue, see https://github.com/sympy/sympy/pull/15799
24
+ # should work once that is solved
25
+ # d = rr.listofpoly[0]
26
+ # assert rr == d
27
+
28
+ d2 = rr2.listofpoly[0]
29
+ assert not rr2 == d2
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