def test_lon_pole():
tan = models.Pix2Sky_TAN()
car = models.Pix2Sky_CAR()
sky_positive_lat = coord.SkyCoord(3 * u.deg, 1 * u.deg)
sky_negative_lat = coord.SkyCoord(3 * u.deg, -1 * u.deg)
assert_quantity_allclose(gwutils._compute_lon_pole(sky_positive_lat, tan),
180 * u.deg)
assert_quantity_allclose(gwutils._compute_lon_pole(sky_negative_lat, tan),
180 * u.deg)
assert_quantity_allclose(gwutils._compute_lon_pole(sky_positive_lat, car),
0 * u.deg)
assert_quantity_allclose(gwutils._compute_lon_pole(sky_negative_lat, car),
180 * u.deg)
assert_quantity_allclose(gwutils._compute_lon_pole((0, 34 * u.rad), tan),
180 * u.deg)
assert_allclose(gwutils._compute_lon_pole((1, -34), tan), 180)
def gwcs_3d_galactic_spectral():
"""
This fixture has the axes ordered as lat, spectral, lon.
"""
# lat,wav,lon
crpix1, crpix2, crpix3 = 29, 39, 44
crval1, crval2, crval3 = 10, 20, 25
cdelt1, cdelt2, cdelt3 = -0.01, 0.5, 0.01
shift = models.Shift(-crpix3) & models.Shift(-crpix1)
scale = models.Multiply(cdelt3) & models.Multiply(cdelt1)
proj = models.Pix2Sky_CAR()
skyrot = models.RotateNative2Celestial(crval3, 90 + crval1, 180)
celestial = shift | scale | proj | skyrot
wave_model = models.Shift(-crpix2) | models.Multiply(
cdelt2) | models.Shift(crval2)
transform = models.Mapping(
(2, 0, 1)) | celestial & wave_model | models.Mapping((1, 2, 0))
transform.bounding_box = ((5, 50), (-2, 45), (-1, 35))
sky_frame = cf.CelestialFrame(axes_order=(2, 0),
reference_frame=coord.Galactic(),
axes_names=("Longitude", "Latitude"))
wave_frame = cf.SpectralFrame(axes_order=(1, ),
unit=u.Hz,
axes_names=("Frequency", ))
frame = cf.CompositeFrame([sky_frame, wave_frame])
detector_frame = cf.CoordinateFrame(name="detector",
naxes=3,
axes_order=(0, 1, 2),
axes_type=("pixel", "pixel", "pixel"),
unit=(u.pix, u.pix, u.pix))
owcs = wcs.WCS(forward_transform=transform,
output_frame=frame,
input_frame=detector_frame)
owcs.array_shape = (30, 20, 10)
owcs.pixel_shape = (10, 20, 30)
return owcs
