def _get_coord_systems(expr):
g = preorder_traversal(expr)
ret = set([])
for i in g:
if isinstance(i, CoordSys3D):
ret.add(i)
g.skip()
return frozenset(ret)
def _get_coord_systems(expr):
g = preorder_traversal(expr)
ret = set([])
for i in g:
if isinstance(i, CoordSys3D):
ret.add(i)
g.skip()
return frozenset(ret)
def symbolic_difference(ex1, ex2, thr=9):
dif = sp.N(sympy_simplify(ex2 - ex1))
for a in sp.preorder_traversal(dif):
if isinstance(a, sp.Float):
dif = dif.subs(a, round(a, thr))
return sympy_simplify(dif)