File size: 5,607 Bytes
6a86ad5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
from sympy.combinatorics import Permutation
from sympy.core.expr import unchanged
from sympy.matrices import Matrix
from sympy.matrices.expressions import \
    MatMul, BlockDiagMatrix, Determinant, Inverse
from sympy.matrices.expressions.matexpr import MatrixSymbol
from sympy.matrices.expressions.special import ZeroMatrix, OneMatrix, Identity
from sympy.matrices.expressions.permutation import \
    MatrixPermute, PermutationMatrix
from sympy.testing.pytest import raises
from sympy.core.symbol import Symbol


def test_PermutationMatrix_basic():
    p = Permutation([1, 0])
    assert unchanged(PermutationMatrix, p)
    raises(ValueError, lambda: PermutationMatrix((0, 1, 2)))
    assert PermutationMatrix(p).as_explicit() == Matrix([[0, 1], [1, 0]])
    assert isinstance(PermutationMatrix(p)*MatrixSymbol('A', 2, 2), MatMul)


def test_PermutationMatrix_matmul():
    p = Permutation([1, 2, 0])
    P = PermutationMatrix(p)
    M = Matrix([[0, 1, 2], [3, 4, 5], [6, 7, 8]])
    assert (P*M).as_explicit() == P.as_explicit()*M
    assert (M*P).as_explicit() == M*P.as_explicit()

    P1 = PermutationMatrix(Permutation([1, 2, 0]))
    P2 = PermutationMatrix(Permutation([2, 1, 0]))
    P3 = PermutationMatrix(Permutation([1, 0, 2]))
    assert P1*P2 == P3


def test_PermutationMatrix_matpow():
    p1 = Permutation([1, 2, 0])
    P1 = PermutationMatrix(p1)
    p2 = Permutation([2, 0, 1])
    P2 = PermutationMatrix(p2)
    assert P1**2 == P2
    assert P1**3 == Identity(3)


def test_PermutationMatrix_identity():
    p = Permutation([0, 1])
    assert PermutationMatrix(p).is_Identity

    p = Permutation([1, 0])
    assert not PermutationMatrix(p).is_Identity


def test_PermutationMatrix_determinant():
    P = PermutationMatrix(Permutation([0, 1, 2]))
    assert Determinant(P).doit() == 1
    P = PermutationMatrix(Permutation([0, 2, 1]))
    assert Determinant(P).doit() == -1
    P = PermutationMatrix(Permutation([2, 0, 1]))
    assert Determinant(P).doit() == 1


def test_PermutationMatrix_inverse():
    P = PermutationMatrix(Permutation(0, 1, 2))
    assert Inverse(P).doit() == PermutationMatrix(Permutation(0, 2, 1))


def test_PermutationMatrix_rewrite_BlockDiagMatrix():
    P = PermutationMatrix(Permutation([0, 1, 2, 3, 4, 5]))
    P0 = PermutationMatrix(Permutation([0]))
    assert P.rewrite(BlockDiagMatrix) == \
        BlockDiagMatrix(P0, P0, P0, P0, P0, P0)

    P = PermutationMatrix(Permutation([0, 1, 3, 2, 4, 5]))
    P10 = PermutationMatrix(Permutation(0, 1))
    assert P.rewrite(BlockDiagMatrix) == \
        BlockDiagMatrix(P0, P0, P10, P0, P0)

    P = PermutationMatrix(Permutation([1, 0, 3, 2, 5, 4]))
    assert P.rewrite(BlockDiagMatrix) == \
        BlockDiagMatrix(P10, P10, P10)

    P = PermutationMatrix(Permutation([0, 4, 3, 2, 1, 5]))
    P3210 = PermutationMatrix(Permutation([3, 2, 1, 0]))
    assert P.rewrite(BlockDiagMatrix) == \
        BlockDiagMatrix(P0, P3210, P0)

    P = PermutationMatrix(Permutation([0, 4, 2, 3, 1, 5]))
    P3120 = PermutationMatrix(Permutation([3, 1, 2, 0]))
    assert P.rewrite(BlockDiagMatrix) == \
        BlockDiagMatrix(P0, P3120, P0)

    P = PermutationMatrix(Permutation(0, 3)(1, 4)(2, 5))
    assert P.rewrite(BlockDiagMatrix) == BlockDiagMatrix(P)


def test_MartrixPermute_basic():
    p = Permutation(0, 1)
    P = PermutationMatrix(p)
    A = MatrixSymbol('A', 2, 2)

    raises(ValueError, lambda: MatrixPermute(Symbol('x'), p))
    raises(ValueError, lambda: MatrixPermute(A, Symbol('x')))

    assert MatrixPermute(A, P) == MatrixPermute(A, p)
    raises(ValueError, lambda: MatrixPermute(A, p, 2))

    pp = Permutation(0, 1, size=3)
    assert MatrixPermute(A, pp) == MatrixPermute(A, p)
    pp = Permutation(0, 1, 2)
    raises(ValueError, lambda: MatrixPermute(A, pp))


def test_MatrixPermute_shape():
    p = Permutation(0, 1)
    A = MatrixSymbol('A', 2, 3)
    assert MatrixPermute(A, p).shape == (2, 3)


def test_MatrixPermute_explicit():
    p = Permutation(0, 1, 2)
    A = MatrixSymbol('A', 3, 3)
    AA = A.as_explicit()
    assert MatrixPermute(A, p, 0).as_explicit() == \
        AA.permute(p, orientation='rows')
    assert MatrixPermute(A, p, 1).as_explicit() == \
        AA.permute(p, orientation='cols')


def test_MatrixPermute_rewrite_MatMul():
    p = Permutation(0, 1, 2)
    A = MatrixSymbol('A', 3, 3)

    assert MatrixPermute(A, p, 0).rewrite(MatMul).as_explicit() == \
        MatrixPermute(A, p, 0).as_explicit()
    assert MatrixPermute(A, p, 1).rewrite(MatMul).as_explicit() == \
        MatrixPermute(A, p, 1).as_explicit()


def test_MatrixPermute_doit():
    p = Permutation(0, 1, 2)
    A = MatrixSymbol('A', 3, 3)
    assert MatrixPermute(A, p).doit() == MatrixPermute(A, p)

    p = Permutation(0, size=3)
    A = MatrixSymbol('A', 3, 3)
    assert MatrixPermute(A, p).doit().as_explicit() == \
        MatrixPermute(A, p).as_explicit()

    p = Permutation(0, 1, 2)
    A = Identity(3)
    assert MatrixPermute(A, p, 0).doit().as_explicit() == \
        MatrixPermute(A, p, 0).as_explicit()
    assert MatrixPermute(A, p, 1).doit().as_explicit() == \
        MatrixPermute(A, p, 1).as_explicit()

    A = ZeroMatrix(3, 3)
    assert MatrixPermute(A, p).doit() == A
    A = OneMatrix(3, 3)
    assert MatrixPermute(A, p).doit() == A

    A = MatrixSymbol('A', 4, 4)
    p1 = Permutation(0, 1, 2, 3)
    p2 = Permutation(0, 2, 3, 1)
    expr = MatrixPermute(MatrixPermute(A, p1, 0), p2, 0)
    assert expr.as_explicit() == expr.doit().as_explicit()
    expr = MatrixPermute(MatrixPermute(A, p1, 1), p2, 1)
    assert expr.as_explicit() == expr.doit().as_explicit()