def test_matrixsymbol_from_symbol():
# The label should be preserved during doit and subs
A_label = Symbol('A', complex=True)
A = MatrixSymbol(A_label, 2, 2)
A_1 = A.doit()
A_2 = A.subs(2, 3)
assert A_1.args == A.args
assert A_2.args[0] == A.args[0]
def test_subs():
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, l)
C = MatrixSymbol('C', m, l)
assert A.subs(n, m).shape == (m, m)
assert (A*B).subs(B, C) == A*C
assert (A*B).subs(l, n).is_square
def test_subs():
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, l)
C = MatrixSymbol('C', m, l)
assert A.subs(n, m).shape == (m, m)
assert (A * B).subs(B, C) == A * C
assert (A * B).subs(l, n).is_square
def test_subs():
n, m, l = symbols('n m l', integer=True)
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, l)
C = MatrixSymbol('C', m, l)
assert A.subs(n,m).shape == (m,m)
assert (A*B).subs(B,C) == A*C
assert (A*B).subs(l,n).is_square
def test_subs():
n, m, l = symbols('n m l', integer=True)
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, l)
C = MatrixSymbol('C', m, l)
assert A.subs(n, m).shape == (m, m)
assert (A * B).subs(B, C) == A * C
assert (A * B).subs(l, n).is_square
def test_subs():
n, m, l = symbols("n m l", integer=True)
A = MatrixSymbol("A", n, m)
B = MatrixSymbol("B", m, l)
C = MatrixSymbol("C", m, l)
assert A.subs(n, m).shape == (m, m)
assert (A * B).subs(B, C) == A * C
assert (A * B).subs(l, n).is_square
def test_matexpr_subs():
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, l)
C = MatrixSymbol('C', m, l)
assert A.subs(n, m).shape == (m, m)
assert (A * B).subs(B, C) == A * C
assert (A * B).subs(l, n).is_square
W = MatrixSymbol("W", 3, 3)
X = MatrixSymbol("X", 2, 2)
Y = MatrixSymbol("Y", 1, 2)
Z = MatrixSymbol("Z", n, 2)
# no restrictions on Symbol replacement
assert X.subs(X, Y) == Y
# it might be better to just change the name
y = Str('y')
assert X.subs(Str("X"), y).args == (y, 2, 2)
# it's ok to introduce a wider matrix
assert X[1, 1].subs(X, W) == W[1, 1]
# but for a given MatrixExpression, only change
# name if indexing on the new shape is valid.
# Here, X is 2,2; Y is 1,2 and Y[1, 1] is out
# of range so an error is raised
raises(IndexError, lambda: X[1, 1].subs(X, Y))
# here, [0, 1] is in range so the subs succeeds
assert X[0, 1].subs(X, Y) == Y[0, 1]
# and here the size of n will accept any index
# in the first position
assert W[2, 1].subs(W, Z) == Z[2, 1]
# but not in the second position
raises(IndexError, lambda: W[2, 2].subs(W, Z))
# any matrix should raise if invalid
raises(IndexError, lambda: W[2, 2].subs(W, zeros(2)))
A = SparseMatrix([[1, 2], [3, 4]])
B = Matrix([[1, 2], [3, 4]])
C, D = MatrixSymbol('C', 2, 2), MatrixSymbol('D', 2, 2)
assert (C * D).subs({C: A, D: B}) == MatMul(A, B)
def test_subs():
A = MatrixSymbol('A', n, m)
B = MatrixSymbol('B', m, l)
C = MatrixSymbol('C', m, l)
assert A.subs(n, m).shape == (m, m)
assert (A * B).subs(B, C) == A * C
assert (A * B).subs(l, n).is_square
A = SparseMatrix([[1, 2], [3, 4]])
B = Matrix([[1, 2], [3, 4]])
C, D = MatrixSymbol('C', 2, 2), MatrixSymbol('D', 2, 2)
assert (C * D).subs({C: A, D: B}) == MatMul(A, B)