def test_2d():
world = np.ones((10, 2))
w1 = WCSWorld2PixelTransform(WCS2D) + Affine2D()
pixel = w1.transform(world)
world_2 = w1.inverted().transform(pixel)
np.testing.assert_allclose(world, world_2)
def test_3d():
world = np.ones((10, 2))
w1 = WCSWorld2PixelTransform(WCS3D[:, 0, :]) + Affine2D()
pixel = w1.transform(world)
world_2 = w1.inverted().transform(pixel)
np.testing.assert_allclose(world[:, 0], world_2[:, 0])
np.testing.assert_allclose(world[:, 1], world_2[:, 1])
def test_shorthand_inversion():
"""
Test that the Matplotlib subtraction shorthand for composing and inverting
transformations works.
"""
w1 = WCS(naxis=2)
w1.wcs.ctype = ['RA---TAN', 'DEC--TAN']
w1.wcs.crpix = [256.0, 256.0]
w1.wcs.cdelt = [-0.05, 0.05]
w1.wcs.crval = [120.0, -19.0]
w2 = WCS(naxis=2)
w2.wcs.ctype = ['RA---SIN', 'DEC--SIN']
w2.wcs.crpix = [256.0, 256.0]
w2.wcs.cdelt = [-0.05, 0.05]
w2.wcs.crval = [235.0, +23.7]
t1 = WCSWorld2PixelTransform(w1)
t2 = WCSWorld2PixelTransform(w2)
assert t1 - t2 == t1 + t2.inverted()
assert t1 - t2 != t2.inverted() + t1
assert t1 - t1 == IdentityTransform()