def _collect_bilinear(self, expr, bilin, quad):
if not expr.is_expression_type():
return
if type(expr) is ProductExpression:
if len(expr._numerator) != 2:
for e in expr._numerator:
self._collect_bilinear(e, bilin, quad)
# No need to check denominator, as this is poly_degree==2
return
if not isinstance(expr._numerator[0], _VarData) or \
not isinstance(expr._numerator[1], _VarData):
raise RuntimeError("Cannot yet handle complex subexpressions")
if expr._numerator[0] is expr._numerator[1]:
quad.append((expr, expr._numerator[0]))
else:
bilin.append((expr, expr._numerator[0], expr._numerator[1]))
return
if type(expr) is PowExpression and value(expr._args[1]) == 2:
# Note: directly testing the value of the exponent above is
# safe: we have already verified that this expression is
# polynominal, so the exponent must be constant.
tmp = ProductExpression()
tmp._numerator = [expr._args[0], expr._args[0]]
tmp._denominator = []
expr._args = (tmp, as_numeric(1))
#quad.append( (tmp, tmp._args[0]) )
self._collect_bilinear(tmp, bilin, quad)
return
# All other expression types
for e in expr._args:
self._collect_bilinear(e, bilin, quad)
def _collect_bilinear(self, expr, bilin, quad):
if not expr.is_expression():
return
if type(expr) is _ProductExpression:
if len(expr._numerator) != 2:
for e in expr._numerator:
self._collect_bilinear(e, bilin, quad)
# No need to check denominator, as this is poly_degree==2
return
if not isinstance(expr._numerator[0], _VarData) or \
not isinstance(expr._numerator[1], _VarData):
raise RuntimeError("Cannot yet handle complex subexpressions")
if expr._numerator[0] is expr._numerator[1]:
quad.append( (expr, expr._numerator[0]) )
else:
bilin.append( (expr, expr._numerator[0], expr._numerator[1]) )
return
if type(expr) is _PowExpression and value(expr._args[1]) == 2:
# Note: directly testing the value of the exponent above is
# safe: we have already verified that this expression is
# polynominal, so the exponent must be constant.
tmp = _ProductExpression()
tmp._numerator = [ expr._args[0], expr._args[0] ]
tmp._denominator = []
expr._args = (tmp, as_numeric(1))
#quad.append( (tmp, tmp._args[0]) )
self._collect_bilinear(tmp, bilin, quad)
return
# All other expression types
for e in expr._args:
self._collect_bilinear(e, bilin, quad)