def __call__(self, ps):
    'Returns the arctan2.  The (y, x) coordinate is in the last \n        dimension.'
    meshT = self.mesh(ps).T
    return numpy.arctan2(meshT[0], meshT[1]).T
Returns the arctan2.  The (y, x) coordinate is in the last 
dimension.
def __call__(self, ps):
    'Returns the arctan2.  The (y, x) coordinate is in the last \n        dimension.'
    meshT = self.mesh(ps).T
    return numpy.arctan2(meshT[0], meshT[1]).T