Source code for sympy.matrices.expressions.matadd

from __future__ import print_function, division

from sympy.core.compatibility import reduce
from operator import add

from sympy.core import Add, Basic, sympify
from sympy.functions import adjoint
from sympy.matrices.matrices import MatrixBase
from sympy.matrices.expressions.transpose import transpose
from sympy.strategies import (rm_id, unpack, flatten, sort, condition,
        exhaust, do_one, glom)
from sympy.matrices.expressions.matexpr import MatrixExpr, ShapeError, ZeroMatrix
from sympy.utilities import default_sort_key, sift
from sympy.core.operations import AssocOp

[docs]class MatAdd(MatrixExpr, AssocOp): """A Sum of Matrix Expressions MatAdd inherits from and operates like SymPy Add >>> from sympy import MatAdd, MatrixSymbol >>> A = MatrixSymbol('A', 5, 5) >>> B = MatrixSymbol('B', 5, 5) >>> C = MatrixSymbol('C', 5, 5) >>> MatAdd(A, B, C) A + B + C """ is_MatAdd = True def __new__(cls, *args, **kwargs): args = list(map(sympify, args)) check = kwargs.get('check', True) obj = Basic.__new__(cls, *args) if check: validate(*args) return obj @property def shape(self): return self.args[0].shape def _entry(self, i, j): return Add(*[arg._entry(i, j) for arg in self.args]) def _eval_transpose(self): return MatAdd(*[transpose(arg) for arg in self.args]).doit() def _eval_adjoint(self): return MatAdd(*[adjoint(arg) for arg in self.args]).doit() def _eval_trace(self): from .trace import trace return Add(*[trace(arg) for arg in self.args]).doit() def doit(self, **kwargs): deep = kwargs.get('deep', True) if deep: args = [arg.doit(**kwargs) for arg in self.args] else: args = self.args return canonicalize(MatAdd(*args))
def validate(*args): if not all(arg.is_Matrix for arg in args): raise TypeError("Mix of Matrix and Scalar symbols") A = args[0] for B in args[1:]: if A.shape != B.shape: raise ShapeError("Matrices %s and %s are not aligned"%(A, B)) factor_of = lambda arg: arg.as_coeff_mmul()[0] matrix_of = lambda arg: unpack(arg.as_coeff_mmul()[1]) def combine(cnt, mat): if cnt == 1: return mat else: return cnt * mat def merge_explicit(matadd): """ Merge explicit MatrixBase arguments >>> from sympy import MatrixSymbol, eye, Matrix, MatAdd, pprint >>> from sympy.matrices.expressions.matadd import merge_explicit >>> A = MatrixSymbol('A', 2, 2) >>> B = eye(2) >>> C = Matrix([[1, 2], [3, 4]]) >>> X = MatAdd(A, B, C) >>> pprint(X) [1 0] [1 2] A + [ ] + [ ] [0 1] [3 4] >>> pprint(merge_explicit(X)) [2 2] A + [ ] [3 5] """ groups = sift(matadd.args, lambda arg: isinstance(arg, MatrixBase)) if len(groups[True]) > 1: return MatAdd(*(groups[False] + [reduce(add, groups[True])])) else: return matadd rules = (rm_id(lambda x: x == 0 or isinstance(x, ZeroMatrix)), unpack, flatten, glom(matrix_of, factor_of, combine), merge_explicit, sort(default_sort_key)) canonicalize = exhaust(condition(lambda x: isinstance(x, MatAdd), do_one(*rules)))