'Angular momentum of the particle about the point.
The angular momentum H, about some point O of a particle, P, is given
by:
H = r x m * v
where r is the position vector from point O to the particle P, m is
the mass of the particle, and v is the velocity of the particle in
the inertial frame, N.
Parameters
point : Point
The point about which angular momentum of the particle is desired.
frame : ReferenceFrame
The frame in which angular momentum is desired.
Examples
>>> from sympy.physics.mechanics import Particle, Point, ReferenceFrame
>>> from sympy.physics.mechanics import dynamicsymbols
>>> m, v, r = dynamicsymbols(\'m v r\')
>>> N = ReferenceFrame(\'N\')
>>> O = Point(\'O\')
>>> A = O.locatenew(\'A\', r * N.x)
>>> P = Particle(\'P\', A, m)
>>> P.point.set_vel(N, v * N.y)
>>> P.angular_momentum(O, N)
m*r*v*N.z'

def angular_momentum(self, point, frame):

    return (self.point.pos_from(point) ^ (self.mass * self.point.vel(frame)))
