def _dict_from_expr(expr, opt):
"""Transform an expression into a multinomial form. """
if expr.is_commutative is False:
raise PolynomialError('non-commutative expressions are not supported')
def _is_expandable_pow(expr):
return (expr.is_Pow and expr.exp.is_positive and expr.exp.is_Integer
and expr.base.is_Add)
if opt.expand is not False:
if not isinstance(expr, (Expr, Eq)):
raise PolynomialError('expression must be of type Expr')
expr = expr.expand()
# TODO: Integrate this into expand() itself
while any(
_is_expandable_pow(i) or i.is_Mul and any(
_is_expandable_pow(j) for j in i.args)
for i in Add.make_args(expr)):
expr = expand_multinomial(expr)
while any(i.is_Mul and any(j.is_Add for j in i.args)
for i in Add.make_args(expr)):
expr = expand_mul(expr)
if opt.gens:
rep, gens = _dict_from_expr_if_gens(expr, opt)
else:
rep, gens = _dict_from_expr_no_gens(expr, opt)
return rep, opt.clone({'gens': gens})
def _dict_from_expr(expr, opt):
"""Transform an expression into a multinomial form. """
if expr.is_commutative is False:
raise PolynomialError('non-commutative expressions are not supported')
def _is_expandable_pow(expr):
return (expr.is_Pow and expr.exp.is_positive and expr.exp.is_Integer
and expr.base.is_Add)
if opt.expand is not False:
expr = expr.expand()
# TODO: Integrate this into expand() itself
while any(_is_expandable_pow(i) or i.is_Mul and
any(_is_expandable_pow(j) for j in i.args) for i in
Add.make_args(expr)):
expr = expand_multinomial(expr)
while any(i.is_Mul and any(j.is_Add for j in i.args) for i in Add.make_args(expr)):
expr = expand_mul(expr)
if opt.gens:
rep, gens = _dict_from_expr_if_gens(expr, opt)
else:
rep, gens = _dict_from_expr_no_gens(expr, opt)
return rep, opt.clone({'gens': gens})
