'Transform ``coords`` to coord system ``to_sys``.
See the docstring of ``CoordSystem`` for examples.'

def coord_tuple_transform_to(self, to_sys, coords):

    coords = Matrix(coords)
    if (self != to_sys):
        transf = self.transforms[to_sys]
        coords = transf[1].subs(list(zip(transf[0], coords)))
    return coords
