'Sets the velocity of this point with the 2-point theory.
The 2-point theory for point velocity looks like this:
^N v^P = ^N v^O + ^N omega^B x r^OP
where O and P are both points fixed in frame B, which is rotating in
frame N.
Parameters
otherpoint : Point
The first point of the 2-point theory (O)
outframe : ReferenceFrame
The frame we want this point\'s velocity defined in (N)
fixedframe : ReferenceFrame
The frame in which both points are fixed (B)
Examples
>>> from sympy.physics.vector import Point, ReferenceFrame, dynamicsymbols
>>> q = dynamicsymbols(\'q\')
>>> qd = dynamicsymbols(\'q\', 1)
>>> N = ReferenceFrame(\'N\')
>>> B = N.orientnew(\'B\', \'Axis\', [q, N.z])
>>> O = Point(\'O\')
>>> P = O.locatenew(\'P\', 10 * B.x)
>>> O.set_vel(N, 5 * N.x)
>>> P.v2pt_theory(O, N, B)
5*N.x + 10*q\'*B.y'

def v2pt_theory(self, otherpoint, outframe, fixedframe):

    _check_frame(outframe)
    _check_frame(fixedframe)
    self._check_point(otherpoint)
    dist = self.pos_from(otherpoint)
    v = otherpoint.vel(outframe)
    omega = fixedframe.ang_vel_in(outframe)
    self.set_vel(outframe, (v + (omega ^ dist)))
    return self.vel(outframe)
