File size: 21,962 Bytes
b43ef48
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
from collections import defaultdict

from operator import index as index_

from sympy.core.expr import Expr
from sympy.core.kind import Kind, NumberKind, UndefinedKind
from sympy.core.numbers import Integer, Rational
from sympy.core.sympify import _sympify, SympifyError
from sympy.core.singleton import S
from sympy.polys.domains import ZZ, QQ, EXRAW
from sympy.polys.matrices import DomainMatrix
from sympy.utilities.exceptions import sympy_deprecation_warning
from sympy.utilities.iterables import is_sequence
from sympy.utilities.misc import filldedent

from .common import classof
from .matrices import MatrixBase, MatrixKind, ShapeError


class RepMatrix(MatrixBase):
    """Matrix implementation based on DomainMatrix as an internal representation.

    The RepMatrix class is a superclass for Matrix, ImmutableMatrix,
    SparseMatrix and ImmutableSparseMatrix which are the main usable matrix
    classes in SymPy. Most methods on this class are simply forwarded to
    DomainMatrix.
    """

    #
    # MatrixBase is the common superclass for all of the usable explicit matrix
    # classes in SymPy. The idea is that MatrixBase is an abstract class though
    # and that subclasses will implement the lower-level methods.
    #
    # RepMatrix is a subclass of MatrixBase that uses DomainMatrix as an
    # internal representation and delegates lower-level methods to
    # DomainMatrix. All of SymPy's standard explicit matrix classes subclass
    # RepMatrix and so use DomainMatrix internally.
    #
    # A RepMatrix uses an internal DomainMatrix with the domain set to ZZ, QQ
    # or EXRAW. The EXRAW domain is equivalent to the previous implementation
    # of Matrix that used Expr for the elements. The ZZ and QQ domains are used
    # when applicable just because they are compatible with the previous
    # implementation but are much more efficient. Other domains such as QQ[x]
    # are not used because they differ from Expr in some way (e.g. automatic
    # expansion of powers and products).
    #

    _rep: DomainMatrix

    def __eq__(self, other):
        # Skip sympify for mutable matrices...
        if not isinstance(other, RepMatrix):
            try:
                other = _sympify(other)
            except SympifyError:
                return NotImplemented
            if not isinstance(other, RepMatrix):
                return NotImplemented

        return self._rep.unify_eq(other._rep)

    @classmethod
    def _unify_element_sympy(cls, rep, element):
        domain = rep.domain
        element = _sympify(element)

        if domain != EXRAW:
            # The domain can only be ZZ, QQ or EXRAW
            if element.is_Integer:
                new_domain = domain
            elif element.is_Rational:
                new_domain = QQ
            else:
                new_domain = EXRAW

            # XXX: This converts the domain for all elements in the matrix
            # which can be slow. This happens e.g. if __setitem__ changes one
            # element to something that does not fit in the domain
            if new_domain != domain:
                rep = rep.convert_to(new_domain)
                domain = new_domain

            if domain != EXRAW:
                element = new_domain.from_sympy(element)

        if domain == EXRAW and not isinstance(element, Expr):
            sympy_deprecation_warning(
                """
                non-Expr objects in a Matrix is deprecated. Matrix represents
                a mathematical matrix. To represent a container of non-numeric
                entities, Use a list of lists, TableForm, NumPy array, or some
                other data structure instead.
                """,
                deprecated_since_version="1.9",
                active_deprecations_target="deprecated-non-expr-in-matrix",
                stacklevel=4,
            )

        return rep, element

    @classmethod
    def _dod_to_DomainMatrix(cls, rows, cols, dod, types):

        if not all(issubclass(typ, Expr) for typ in types):
            sympy_deprecation_warning(
                """
                non-Expr objects in a Matrix is deprecated. Matrix represents
                a mathematical matrix. To represent a container of non-numeric
                entities, Use a list of lists, TableForm, NumPy array, or some
                other data structure instead.
                """,
                deprecated_since_version="1.9",
                active_deprecations_target="deprecated-non-expr-in-matrix",
                stacklevel=6,
            )

        rep = DomainMatrix(dod, (rows, cols), EXRAW)

        if all(issubclass(typ, Rational) for typ in types):
            if all(issubclass(typ, Integer) for typ in types):
                rep = rep.convert_to(ZZ)
            else:
                rep = rep.convert_to(QQ)

        return rep

    @classmethod
    def _flat_list_to_DomainMatrix(cls, rows, cols, flat_list):

        elements_dod = defaultdict(dict)
        for n, element in enumerate(flat_list):
            if element != 0:
                i, j = divmod(n, cols)
                elements_dod[i][j] = element

        types = set(map(type, flat_list))

        rep = cls._dod_to_DomainMatrix(rows, cols, elements_dod, types)
        return rep

    @classmethod
    def _smat_to_DomainMatrix(cls, rows, cols, smat):

        elements_dod = defaultdict(dict)
        for (i, j), element in smat.items():
            if element != 0:
                elements_dod[i][j] = element

        types = set(map(type, smat.values()))

        rep = cls._dod_to_DomainMatrix(rows, cols, elements_dod, types)
        return rep

    def flat(self):
        return self._rep.to_sympy().to_list_flat()

    def _eval_tolist(self):
        return self._rep.to_sympy().to_list()

    def _eval_todok(self):
        return self._rep.to_sympy().to_dok()

    def _eval_values(self):
        return list(self.todok().values())

    def copy(self):
        return self._fromrep(self._rep.copy())

    @property
    def kind(self) -> MatrixKind:
        domain = self._rep.domain
        element_kind: Kind
        if domain in (ZZ, QQ):
            element_kind = NumberKind
        elif domain == EXRAW:
            kinds = {e.kind for e in self.values()}
            if len(kinds) == 1:
                [element_kind] = kinds
            else:
                element_kind = UndefinedKind
        else: # pragma: no cover
            raise RuntimeError("Domain should only be ZZ, QQ or EXRAW")
        return MatrixKind(element_kind)

    def _eval_has(self, *patterns):
        # if the matrix has any zeros, see if S.Zero
        # has the pattern.  If _smat is full length,
        # the matrix has no zeros.
        zhas = False
        dok = self.todok()
        if len(dok) != self.rows*self.cols:
            zhas = S.Zero.has(*patterns)
        return zhas or any(value.has(*patterns) for value in dok.values())

    def _eval_is_Identity(self):
        if not all(self[i, i] == 1 for i in range(self.rows)):
            return False
        return len(self.todok()) == self.rows

    def _eval_is_symmetric(self, simpfunc):
        diff = (self - self.T).applyfunc(simpfunc)
        return len(diff.values()) == 0

    def _eval_transpose(self):
        """Returns the transposed SparseMatrix of this SparseMatrix.

        Examples
        ========

        >>> from sympy import SparseMatrix
        >>> a = SparseMatrix(((1, 2), (3, 4)))
        >>> a
        Matrix([
        [1, 2],
        [3, 4]])
        >>> a.T
        Matrix([
        [1, 3],
        [2, 4]])
        """
        return self._fromrep(self._rep.transpose())

    def _eval_col_join(self, other):
        return self._fromrep(self._rep.vstack(other._rep))

    def _eval_row_join(self, other):
        return self._fromrep(self._rep.hstack(other._rep))

    def _eval_extract(self, rowsList, colsList):
        return self._fromrep(self._rep.extract(rowsList, colsList))

    def __getitem__(self, key):
        return _getitem_RepMatrix(self, key)

    @classmethod
    def _eval_zeros(cls, rows, cols):
        rep = DomainMatrix.zeros((rows, cols), ZZ)
        return cls._fromrep(rep)

    @classmethod
    def _eval_eye(cls, rows, cols):
        rep = DomainMatrix.eye((rows, cols), ZZ)
        return cls._fromrep(rep)

    def _eval_add(self, other):
        return classof(self, other)._fromrep(self._rep + other._rep)

    def _eval_matrix_mul(self, other):
        return classof(self, other)._fromrep(self._rep * other._rep)

    def _eval_matrix_mul_elementwise(self, other):
        selfrep, otherrep = self._rep.unify(other._rep)
        newrep = selfrep.mul_elementwise(otherrep)
        return classof(self, other)._fromrep(newrep)

    def _eval_scalar_mul(self, other):
        rep, other = self._unify_element_sympy(self._rep, other)
        return self._fromrep(rep.scalarmul(other))

    def _eval_scalar_rmul(self, other):
        rep, other = self._unify_element_sympy(self._rep, other)
        return self._fromrep(rep.rscalarmul(other))

    def _eval_Abs(self):
        return self._fromrep(self._rep.applyfunc(abs))

    def _eval_conjugate(self):
        rep = self._rep
        domain = rep.domain
        if domain in (ZZ, QQ):
            return self.copy()
        else:
            return self._fromrep(rep.applyfunc(lambda e: e.conjugate()))

    def equals(self, other, failing_expression=False):
        """Applies ``equals`` to corresponding elements of the matrices,
        trying to prove that the elements are equivalent, returning True
        if they are, False if any pair is not, and None (or the first
        failing expression if failing_expression is True) if it cannot
        be decided if the expressions are equivalent or not. This is, in
        general, an expensive operation.

        Examples
        ========

        >>> from sympy import Matrix
        >>> from sympy.abc import x
        >>> A = Matrix([x*(x - 1), 0])
        >>> B = Matrix([x**2 - x, 0])
        >>> A == B
        False
        >>> A.simplify() == B.simplify()
        True
        >>> A.equals(B)
        True
        >>> A.equals(2)
        False

        See Also
        ========
        sympy.core.expr.Expr.equals
        """
        if self.shape != getattr(other, 'shape', None):
            return False

        rv = True
        for i in range(self.rows):
            for j in range(self.cols):
                ans = self[i, j].equals(other[i, j], failing_expression)
                if ans is False:
                    return False
                elif ans is not True and rv is True:
                    rv = ans
        return rv


class MutableRepMatrix(RepMatrix):
    """Mutable matrix based on DomainMatrix as the internal representation"""

    #
    # MutableRepMatrix is a subclass of RepMatrix that adds/overrides methods
    # to make the instances mutable. MutableRepMatrix is a superclass for both
    # MutableDenseMatrix and MutableSparseMatrix.
    #

    is_zero = False

    def __new__(cls, *args, **kwargs):
        return cls._new(*args, **kwargs)

    @classmethod
    def _new(cls, *args, copy=True, **kwargs):
        if copy is False:
            # The input was rows, cols, [list].
            # It should be used directly without creating a copy.
            if len(args) != 3:
                raise TypeError("'copy=False' requires a matrix be initialized as rows,cols,[list]")
            rows, cols, flat_list = args
        else:
            rows, cols, flat_list = cls._handle_creation_inputs(*args, **kwargs)
            flat_list = list(flat_list) # create a shallow copy

        rep = cls._flat_list_to_DomainMatrix(rows, cols, flat_list)

        return cls._fromrep(rep)

    @classmethod
    def _fromrep(cls, rep):
        obj = super().__new__(cls)
        obj.rows, obj.cols = rep.shape
        obj._rep = rep
        return obj

    def copy(self):
        return self._fromrep(self._rep.copy())

    def as_mutable(self):
        return self.copy()

    def __setitem__(self, key, value):
        """

        Examples
        ========

        >>> from sympy import Matrix, I, zeros, ones
        >>> m = Matrix(((1, 2+I), (3, 4)))
        >>> m
        Matrix([
        [1, 2 + I],
        [3,     4]])
        >>> m[1, 0] = 9
        >>> m
        Matrix([
        [1, 2 + I],
        [9,     4]])
        >>> m[1, 0] = [[0, 1]]

        To replace row r you assign to position r*m where m
        is the number of columns:

        >>> M = zeros(4)
        >>> m = M.cols
        >>> M[3*m] = ones(1, m)*2; M
        Matrix([
        [0, 0, 0, 0],
        [0, 0, 0, 0],
        [0, 0, 0, 0],
        [2, 2, 2, 2]])

        And to replace column c you can assign to position c:

        >>> M[2] = ones(m, 1)*4; M
        Matrix([
        [0, 0, 4, 0],
        [0, 0, 4, 0],
        [0, 0, 4, 0],
        [2, 2, 4, 2]])
        """
        rv = self._setitem(key, value)
        if rv is not None:
            i, j, value = rv
            self._rep, value = self._unify_element_sympy(self._rep, value)
            self._rep.rep.setitem(i, j, value)

    def _eval_col_del(self, col):
        self._rep = DomainMatrix.hstack(self._rep[:,:col], self._rep[:,col+1:])
        self.cols -= 1

    def _eval_row_del(self, row):
        self._rep = DomainMatrix.vstack(self._rep[:row,:], self._rep[row+1:, :])
        self.rows -= 1

    def _eval_col_insert(self, col, other):
        other = self._new(other)
        return self.hstack(self[:,:col], other, self[:,col:])

    def _eval_row_insert(self, row, other):
        other = self._new(other)
        return self.vstack(self[:row,:], other, self[row:,:])

    def col_op(self, j, f):
        """In-place operation on col j using two-arg functor whose args are
        interpreted as (self[i, j], i).

        Examples
        ========

        >>> from sympy import eye
        >>> M = eye(3)
        >>> M.col_op(1, lambda v, i: v + 2*M[i, 0]); M
        Matrix([
        [1, 2, 0],
        [0, 1, 0],
        [0, 0, 1]])

        See Also
        ========
        col
        row_op
        """
        for i in range(self.rows):
            self[i, j] = f(self[i, j], i)

    def col_swap(self, i, j):
        """Swap the two given columns of the matrix in-place.

        Examples
        ========

        >>> from sympy import Matrix
        >>> M = Matrix([[1, 0], [1, 0]])
        >>> M
        Matrix([
        [1, 0],
        [1, 0]])
        >>> M.col_swap(0, 1)
        >>> M
        Matrix([
        [0, 1],
        [0, 1]])

        See Also
        ========

        col
        row_swap
        """
        for k in range(0, self.rows):
            self[k, i], self[k, j] = self[k, j], self[k, i]

    def row_op(self, i, f):
        """In-place operation on row ``i`` using two-arg functor whose args are
        interpreted as ``(self[i, j], j)``.

        Examples
        ========

        >>> from sympy import eye
        >>> M = eye(3)
        >>> M.row_op(1, lambda v, j: v + 2*M[0, j]); M
        Matrix([
        [1, 0, 0],
        [2, 1, 0],
        [0, 0, 1]])

        See Also
        ========
        row
        zip_row_op
        col_op

        """
        for j in range(self.cols):
            self[i, j] = f(self[i, j], j)

    def row_swap(self, i, j):
        """Swap the two given rows of the matrix in-place.

        Examples
        ========

        >>> from sympy import Matrix
        >>> M = Matrix([[0, 1], [1, 0]])
        >>> M
        Matrix([
        [0, 1],
        [1, 0]])
        >>> M.row_swap(0, 1)
        >>> M
        Matrix([
        [1, 0],
        [0, 1]])

        See Also
        ========

        row
        col_swap
        """
        for k in range(0, self.cols):
            self[i, k], self[j, k] = self[j, k], self[i, k]

    def zip_row_op(self, i, k, f):
        """In-place operation on row ``i`` using two-arg functor whose args are
        interpreted as ``(self[i, j], self[k, j])``.

        Examples
        ========

        >>> from sympy import eye
        >>> M = eye(3)
        >>> M.zip_row_op(1, 0, lambda v, u: v + 2*u); M
        Matrix([
        [1, 0, 0],
        [2, 1, 0],
        [0, 0, 1]])

        See Also
        ========
        row
        row_op
        col_op

        """
        for j in range(self.cols):
            self[i, j] = f(self[i, j], self[k, j])

    def copyin_list(self, key, value):
        """Copy in elements from a list.

        Parameters
        ==========

        key : slice
            The section of this matrix to replace.
        value : iterable
            The iterable to copy values from.

        Examples
        ========

        >>> from sympy import eye
        >>> I = eye(3)
        >>> I[:2, 0] = [1, 2] # col
        >>> I
        Matrix([
        [1, 0, 0],
        [2, 1, 0],
        [0, 0, 1]])
        >>> I[1, :2] = [[3, 4]]
        >>> I
        Matrix([
        [1, 0, 0],
        [3, 4, 0],
        [0, 0, 1]])

        See Also
        ========

        copyin_matrix
        """
        if not is_sequence(value):
            raise TypeError("`value` must be an ordered iterable, not %s." % type(value))
        return self.copyin_matrix(key, type(self)(value))

    def copyin_matrix(self, key, value):
        """Copy in values from a matrix into the given bounds.

        Parameters
        ==========

        key : slice
            The section of this matrix to replace.
        value : Matrix
            The matrix to copy values from.

        Examples
        ========

        >>> from sympy import Matrix, eye
        >>> M = Matrix([[0, 1], [2, 3], [4, 5]])
        >>> I = eye(3)
        >>> I[:3, :2] = M
        >>> I
        Matrix([
        [0, 1, 0],
        [2, 3, 0],
        [4, 5, 1]])
        >>> I[0, 1] = M
        >>> I
        Matrix([
        [0, 0, 1],
        [2, 2, 3],
        [4, 4, 5]])

        See Also
        ========

        copyin_list
        """
        rlo, rhi, clo, chi = self.key2bounds(key)
        shape = value.shape
        dr, dc = rhi - rlo, chi - clo
        if shape != (dr, dc):
            raise ShapeError(filldedent("The Matrix `value` doesn't have the "
                                        "same dimensions "
                                        "as the in sub-Matrix given by `key`."))

        for i in range(value.rows):
            for j in range(value.cols):
                self[i + rlo, j + clo] = value[i, j]

    def fill(self, value):
        """Fill self with the given value.

        Notes
        =====

        Unless many values are going to be deleted (i.e. set to zero)
        this will create a matrix that is slower than a dense matrix in
        operations.

        Examples
        ========

        >>> from sympy import SparseMatrix
        >>> M = SparseMatrix.zeros(3); M
        Matrix([
        [0, 0, 0],
        [0, 0, 0],
        [0, 0, 0]])
        >>> M.fill(1); M
        Matrix([
        [1, 1, 1],
        [1, 1, 1],
        [1, 1, 1]])

        See Also
        ========

        zeros
        ones
        """
        value = _sympify(value)
        if not value:
            self._rep = DomainMatrix.zeros(self.shape, EXRAW)
        else:
            elements_dod = {i: {j: value for j in range(self.cols)} for i in range(self.rows)}
            self._rep = DomainMatrix(elements_dod, self.shape, EXRAW)


def _getitem_RepMatrix(self, key):
    """Return portion of self defined by key. If the key involves a slice
    then a list will be returned (if key is a single slice) or a matrix
    (if key was a tuple involving a slice).

    Examples
    ========

    >>> from sympy import Matrix, I
    >>> m = Matrix([
    ... [1, 2 + I],
    ... [3, 4    ]])

    If the key is a tuple that does not involve a slice then that element
    is returned:

    >>> m[1, 0]
    3

    When a tuple key involves a slice, a matrix is returned. Here, the
    first column is selected (all rows, column 0):

    >>> m[:, 0]
    Matrix([
    [1],
    [3]])

    If the slice is not a tuple then it selects from the underlying
    list of elements that are arranged in row order and a list is
    returned if a slice is involved:

    >>> m[0]
    1
    >>> m[::2]
    [1, 3]
    """
    if isinstance(key, tuple):
        i, j = key
        try:
            return self._rep.getitem_sympy(index_(i), index_(j))
        except (TypeError, IndexError):
            if (isinstance(i, Expr) and not i.is_number) or (isinstance(j, Expr) and not j.is_number):
                if ((j < 0) is True) or ((j >= self.shape[1]) is True) or\
                   ((i < 0) is True) or ((i >= self.shape[0]) is True):
                    raise ValueError("index out of boundary")
                from sympy.matrices.expressions.matexpr import MatrixElement
                return MatrixElement(self, i, j)

            if isinstance(i, slice):
                i = range(self.rows)[i]
            elif is_sequence(i):
                pass
            else:
                i = [i]
            if isinstance(j, slice):
                j = range(self.cols)[j]
            elif is_sequence(j):
                pass
            else:
                j = [j]
            return self.extract(i, j)

    else:
        # Index/slice like a flattened list
        rows, cols = self.shape

        # Raise the appropriate exception:
        if not rows * cols:
            return [][key]

        rep = self._rep.rep
        domain = rep.domain
        is_slice = isinstance(key, slice)

        if is_slice:
            values = [rep.getitem(*divmod(n, cols)) for n in range(rows * cols)[key]]
        else:
            values = [rep.getitem(*divmod(index_(key), cols))]

        if domain != EXRAW:
            to_sympy = domain.to_sympy
            values = [to_sympy(val) for val in values]

        if is_slice:
            return values
        else:
            return values[0]