def test_propagate_from_plane_to_plane_reverse():
r = Ray([1,0,0], [0,0,1], wavelength, energy)
r.propagate_from_plane_to_plane( 10, normalise([ 1,2,1]), normalise([-1,3,1]))
r.propagate_from_plane_to_plane(-10, normalise([-1,3,1]), normalise([ 1,2,1]))
assert allclose(r.position, [1,0,0])
def test_align_to_plane():
r = Ray([1,0,0], [0,0,1], wavelength, energy)
r.propagate_from_plane_to_plane(0, array([0,0,1]), normalise([-1,0,1]))
assert allclose(r.position, [1,0,1])
