'Returns a Vector equivalent to this one, expressed in otherframe.
Uses the global express method.
Parameters
otherframe : ReferenceFrame
The frame for this Vector to be described in
variables : boolean
If True, the coordinate symbols(if present) in this Vector
are re-expressed in terms otherframe
Examples
>>> from sympy.physics.vector import ReferenceFrame, Vector, dynamicsymbols
>>> q1 = dynamicsymbols(\'q1\')
>>> N = ReferenceFrame(\'N\')
>>> A = N.orientnew(\'A\', \'Axis\', [q1, N.y])
>>> A.x.express(N)
cos(q1)*N.x - sin(q1)*N.z'

def express(self, otherframe, variables=False):

    from sympy.physics.vector import express
    return express(self, otherframe, variables=variables)
