def block_collapse(expr):
"""Evaluates a block matrix expression
>>> from sympy import MatrixSymbol, BlockMatrix, symbols, \
Identity, Matrix, ZeroMatrix, block_collapse
>>> n,m,l = symbols('n m l')
>>> X = MatrixSymbol('X', n, n)
>>> Y = MatrixSymbol('Y', m ,m)
>>> Z = MatrixSymbol('Z', n, m)
>>> B = BlockMatrix([[X, Z], [ZeroMatrix(m, n), Y]])
>>> print B
[X, Z]
[0, Y]
>>> C = BlockMatrix([[Identity(n), Z]])
>>> print C
[I, Z]
>>> print block_collapse(C*B)
[X, Z + Z*Y]
"""
rule = canon(typed({MatAdd: do_one(bc_matadd, bc_block_plus_ident),
MatMul: do_one(bc_matmul, bc_dist),
MatPow: bc_matpow,
BlockMatrix: bc_unpack}))
result = rule(expr)
try:
return result.canonicalize()
except AttributeError:
return result
def block_collapse(expr):
"""Evaluates a block matrix expression
>>> from sympy import MatrixSymbol, BlockMatrix, symbols, \
Identity, Matrix, ZeroMatrix, block_collapse
>>> n,m,l = symbols('n m l')
>>> X = MatrixSymbol('X', n, n)
>>> Y = MatrixSymbol('Y', m ,m)
>>> Z = MatrixSymbol('Z', n, m)
>>> B = BlockMatrix([[X, Z], [ZeroMatrix(m, n), Y]])
>>> print B
[X, Z]
[0, Y]
>>> C = BlockMatrix([[Identity(n), Z]])
>>> print C
[I, Z]
>>> print block_collapse(C*B)
[X, Z + Z*Y]
"""
rule = canon(
typed({
MatAdd: do_one(bc_matadd, bc_block_plus_ident),
MatMul: do_one(bc_matmul, bc_dist),
BlockMatrix: bc_unpack
}))
result = rule(expr)
try:
return result.doit()
except AttributeError:
return result
def test_typed():
class A(Basic):
pass
class B(Basic):
pass
rmzeros = rm_id(lambda x: x == 0)
rmones = rm_id(lambda x: x == 1)
remove_something = typed({A: rmzeros, B: rmones})
assert remove_something(A(0, 1)) == A(1)
assert remove_something(B(0, 1)) == B(0)
def test_typed():
class A(Basic):
pass
class B(Basic):
pass
rmzeros = rm_id(lambda x: x == 0)
rmones = rm_id(lambda x: x == 1)
remove_something = typed({A: rmzeros, B: rmones})
assert remove_something(A(0, 1)) == A(1)
assert remove_something(B(0, 1)) == B(0)