def test_wcs_to_celestial_frame():
# Import astropy.coordinates here to avoid circular imports
from astropy.coordinates.builtin_frames import ICRS, ITRS, FK5, FK4, Galactic
mywcs = WCS(naxis=2)
mywcs.wcs.set()
with pytest.raises(ValueError,
match="Could not determine celestial frame "
"corresponding to the specified WCS object"):
assert wcs_to_celestial_frame(mywcs) is None
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['XOFFSET', 'YOFFSET']
mywcs.wcs.set()
with pytest.raises(ValueError):
assert wcs_to_celestial_frame(mywcs) is None
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.equinox = 1987.
mywcs.wcs.set()
print(mywcs.to_header())
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, FK5)
assert frame.equinox == Time(1987., format='jyear')
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.equinox = 1982
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, FK4)
assert frame.equinox == Time(1982., format='byear')
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['GLON-SIN', 'GLAT-SIN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, Galactic)
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['TLON-CAR', 'TLAT-CAR']
mywcs.wcs.dateobs = '2017-08-17T12:41:04.430'
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ITRS)
assert frame.obstime == Time('2017-08-17T12:41:04.430')
for equinox in [np.nan, 1987, 1982]:
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.radesys = 'ICRS'
mywcs.wcs.equinox = equinox
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
# Flipped order
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['DEC--TAN', 'RA---TAN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
# More than two dimensions
mywcs = WCS(naxis=3)
mywcs.wcs.ctype = ['DEC--TAN', 'VELOCITY', 'RA---TAN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
mywcs = WCS(naxis=3)
mywcs.wcs.ctype = ['GLAT-CAR', 'VELOCITY', 'GLON-CAR']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, Galactic)
def test_wcs_to_celestial_frame():
# Import astropy.coordinates here to avoid circular imports
from astropy.coordinates.builtin_frames import ICRS, ITRS, FK5, FK4, Galactic
mywcs = WCS(naxis=2)
mywcs.wcs.set()
with pytest.raises(ValueError) as exc:
assert wcs_to_celestial_frame(mywcs) is None
assert exc.value.args[0] == "Could not determine celestial frame corresponding to the specified WCS object"
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['XOFFSET', 'YOFFSET']
mywcs.wcs.set()
with pytest.raises(ValueError):
assert wcs_to_celestial_frame(mywcs) is None
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.equinox = 1987.
mywcs.wcs.set()
print(mywcs.to_header())
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, FK5)
assert frame.equinox == Time(1987., format='jyear')
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.equinox = 1982
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, FK4)
assert frame.equinox == Time(1982., format='byear')
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['GLON-SIN', 'GLAT-SIN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, Galactic)
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['TLON-CAR', 'TLAT-CAR']
mywcs.wcs.dateobs = '2017-08-17T12:41:04.430'
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ITRS)
assert frame.obstime == Time('2017-08-17T12:41:04.430')
for equinox in [np.nan, 1987, 1982]:
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
mywcs.wcs.radesys = 'ICRS'
mywcs.wcs.equinox = equinox
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
# Flipped order
mywcs = WCS(naxis=2)
mywcs.wcs.ctype = ['DEC--TAN', 'RA---TAN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
# More than two dimensions
mywcs = WCS(naxis=3)
mywcs.wcs.ctype = ['DEC--TAN', 'VELOCITY', 'RA---TAN']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, ICRS)
mywcs = WCS(naxis=3)
mywcs.wcs.ctype = ['GLAT-CAR', 'VELOCITY', 'GLON-CAR']
mywcs.wcs.set()
frame = wcs_to_celestial_frame(mywcs)
assert isinstance(frame, Galactic)
