def evolve(self, points, t):
# Given points at time 0, return points at time t.
lats = geometry.points_to_latitudes(points/self.radius, self.axis)
vels = physics.fluid_rotation(self.eq_angvel, self.polar_angvel, lats)
result = np.zeros(points.shape)
mat = geometry.rotation_matrix(-vels * t, self.axis)
return np.dot( points, mat.transpose() )
def angvel(self, points):
# Takes points to angular velocities. Trivial constant function in this case.
lats = geometry.points_to_latitudes(points/self.radius, self.axis)
vels = physics.fluid_rotation(self.eq_angvel, self.polar_angvel, lats)
return np.kron(self.axis, vels.reshape(len(vels), 1))
