'The direction ratio of a given line in 3D.
See Also
sympy.geometry.line.Line.equation
Examples
>>> from sympy import Point3D, Line3D
>>> p1, p2 = Point3D(0, 0, 0), Point3D(5, 3, 1)
>>> l = Line3D(p1, p2)
>>> l.direction_ratio
[5, 3, 1]'

@property
def direction_ratio(self):

    (p1, p2) = self.points
    return p1.direction_ratio(p2)
