def test_altaz_attribute_transforms():
"""Test transforms between AltAz frames with different attributes."""
el1 = EarthLocation(0 * u.deg, 0 * u.deg, 0 * u.m)
origin1 = AltAz(0 * u.deg,
0 * u.deg,
obstime=Time("2000-01-01T12:00:00"),
location=el1)
frame1 = SkyOffsetFrame(origin=origin1)
coo1 = SkyCoord(1 * u.deg, 1 * u.deg, frame=frame1)
el2 = EarthLocation(0 * u.deg, 0 * u.deg, 0 * u.m)
origin2 = AltAz(0 * u.deg,
0 * u.deg,
obstime=Time("2000-01-01T11:00:00"),
location=el2)
frame2 = SkyOffsetFrame(origin=origin2)
coo2 = coo1.transform_to(frame2)
coo2_expected = [1.22522446, 0.70624298] * u.deg
assert_allclose([coo2.lon.wrap_at(180 * u.deg), coo2.lat],
coo2_expected,
atol=convert_precision)
el3 = EarthLocation(0 * u.deg, 90 * u.deg, 0 * u.m)
origin3 = AltAz(0 * u.deg,
90 * u.deg,
obstime=Time("2000-01-01T12:00:00"),
location=el3)
frame3 = SkyOffsetFrame(origin=origin3)
coo3 = coo2.transform_to(frame3)
assert_allclose([coo3.lon.wrap_at(180 * u.deg), coo3.lat],
[1 * u.deg, 1 * u.deg],
atol=convert_precision)
def test_skyoffset_names():
origin1 = ICRS(45 * u.deg, 45 * u.deg)
aframe1 = SkyOffsetFrame(origin=origin1)
assert type(aframe1).__name__ == 'SkyOffsetICRS'
origin2 = Galactic(45 * u.deg, 45 * u.deg)
aframe2 = SkyOffsetFrame(origin=origin2)
assert type(aframe2).__name__ == 'SkyOffsetGalactic'
def test_skyoffset_lonwrap():
origin = ICRS(45*u.deg, 45*u.deg)
sc = SkyCoord(190*u.deg, -45*u.deg, frame=SkyOffsetFrame(origin=origin))
assert sc.lon < 180 * u.deg
sc2 = SkyCoord(-10*u.deg, -45*u.deg, frame=SkyOffsetFrame(origin=origin))
assert sc2.lon < 180 * u.deg
sc3 = sc.realize_frame(sc.represent_as('cartesian'))
assert sc3.lon < 180 * u.deg
sc4 = sc2.realize_frame(sc2.represent_as('cartesian'))
assert sc4.lon < 180 * u.deg
def test_skyoffset_functional_ra():
# we do the 12)[1:-1] business because sometimes machine precision issues
# lead to results that are either ~0 or ~360, which mucks up the final
# comparison and leads to spurious failures. So this just avoids that by
# staying away from the edges
input_ra = np.linspace(0, 360, 12)[1:-1]
input_dec = np.linspace(-90, 90, 12)[1:-1]
icrs_coord = ICRS(ra=input_ra * u.deg,
dec=input_dec * u.deg,
distance=1. * u.kpc)
for ra in np.linspace(0, 360, 24):
# expected rotation
expected = ICRS(ra=np.linspace(0 - ra, 360 - ra, 12)[1:-1] * u.deg,
dec=np.linspace(-90, 90, 12)[1:-1] * u.deg,
distance=1. * u.kpc)
expected_xyz = expected.cartesian.xyz
# actual transformation to the frame
skyoffset_frame = SkyOffsetFrame(origin=ICRS(ra * u.deg, 0 * u.deg))
actual = icrs_coord.transform_to(skyoffset_frame)
actual_xyz = actual.cartesian.xyz
# back to ICRS
roundtrip = actual.transform_to(ICRS())
roundtrip_xyz = roundtrip.cartesian.xyz
# Verify
assert_allclose(actual_xyz, expected_xyz, atol=1E-5 * u.kpc)
assert_allclose(icrs_coord.ra, roundtrip.ra, atol=1E-5 * u.deg)
assert_allclose(icrs_coord.dec, roundtrip.dec, atol=1E-5 * u.deg)
assert_allclose(icrs_coord.distance,
roundtrip.distance,
atol=1E-5 * u.kpc)
def test_skyoffset_velocity():
c = ICRS(ra=170.9*u.deg, dec=-78.4*u.deg,
pm_ra_cosdec=74.4134*u.mas/u.yr,
pm_dec=-93.2342*u.mas/u.yr)
skyoffset_frame = SkyOffsetFrame(origin=c)
c_skyoffset = c.transform_to(skyoffset_frame)
assert_allclose(c_skyoffset.pm_lon_coslat, c.pm_ra_cosdec)
assert_allclose(c_skyoffset.pm_lat, c.pm_dec)
def test_rotation(rotation, expectedlatlon):
origin = ICRS(45*u.deg, 45*u.deg)
target = ICRS(45*u.deg, 46*u.deg)
aframe = SkyOffsetFrame(origin=origin, rotation=rotation)
trans = target.transform_to(aframe)
assert_allclose([trans.lon.wrap_at(180*u.deg), trans.lat],
expectedlatlon, atol=1e-10*u.deg)
def test_m31_coord_transforms(fromsys, tosys, fromcoo, tocoo):
"""
This tests a variety of coordinate conversions for the Chandra point-source
catalog location of M31 from NED, via SkyOffsetFrames
"""
from_origin = fromsys(fromcoo[0]*u.deg, fromcoo[1]*u.deg,
distance=m31_dist)
from_pos = SkyOffsetFrame(1*u.deg, 1*u.deg, origin=from_origin)
to_origin = tosys(tocoo[0]*u.deg, tocoo[1]*u.deg, distance=m31_dist)
to_astroframe = SkyOffsetFrame(origin=to_origin)
target_pos = from_pos.transform_to(to_astroframe)
assert_allclose(to_origin.separation(target_pos),
np.hypot(from_pos.lon, from_pos.lat),
atol=convert_precision)
roundtrip_pos = target_pos.transform_to(from_pos)
assert_allclose([roundtrip_pos.lon.wrap_at(180*u.deg), roundtrip_pos.lat],
[1.0*u.deg, 1.0*u.deg], atol=convert_precision)
def test_m31_coord_transforms(fromsys, tosys, fromcoo, tocoo):
"""
This tests a variety of coordinate conversions for the Chandra point-source
catalog location of M31 from NED, via SkyOffsetFrames
"""
from_origin = fromsys(fromcoo[0]*u.deg, fromcoo[1]*u.deg,
distance=m31_dist)
from_pos = SkyOffsetFrame(1*u.deg, 1*u.deg, origin=from_origin)
to_origin = tosys(tocoo[0]*u.deg, tocoo[1]*u.deg, distance=m31_dist)
to_astroframe = SkyOffsetFrame(origin=to_origin)
target_pos = from_pos.transform_to(to_astroframe)
assert_allclose(to_origin.separation(target_pos),
np.hypot(from_pos.lon, from_pos.lat),
atol=convert_precision)
roundtrip_pos = target_pos.transform_to(from_pos)
assert_allclose([roundtrip_pos.lon.wrap_at(180*u.deg), roundtrip_pos.lat],
[1.0*u.deg, 1.0*u.deg], atol=convert_precision)
def test_skyoffset_functional_ra_dec():
# we do the 12)[1:-1] business because sometimes machine precision issues
# lead to results that are either ~0 or ~360, which mucks up the final
# comparison and leads to spurious failures. So this just avoids that by
# staying away from the edges
input_ra = np.linspace(0, 360, 12)[1:-1]
input_dec = np.linspace(-90, 90, 12)[1:-1]
input_ra_rad = np.deg2rad(input_ra)
input_dec_rad = np.deg2rad(input_dec)
icrs_coord = ICRS(ra=input_ra * u.deg,
dec=input_dec * u.deg,
distance=1. * u.kpc)
for ra in np.linspace(0, 360, 10):
for dec in np.linspace(-90, 90, 5):
# expected rotation
dec_rad = -np.deg2rad(dec)
ra_rad = np.deg2rad(ra)
expected_x = (-np.sin(input_dec_rad) * np.sin(dec_rad) +
np.cos(input_ra_rad) * np.cos(input_dec_rad) *
np.cos(dec_rad) * np.cos(ra_rad) +
np.sin(input_ra_rad) * np.cos(input_dec_rad) *
np.cos(dec_rad) * np.sin(ra_rad))
expected_y = (
np.sin(input_ra_rad) * np.cos(input_dec_rad) * np.cos(ra_rad) -
np.cos(input_ra_rad) * np.cos(input_dec_rad) * np.sin(ra_rad))
expected_z = (np.sin(input_dec_rad) * np.cos(dec_rad) +
np.sin(dec_rad) * np.cos(ra_rad) *
np.cos(input_ra_rad) * np.cos(input_dec_rad) +
np.sin(dec_rad) * np.sin(ra_rad) *
np.sin(input_ra_rad) * np.cos(input_dec_rad))
expected = SkyCoord(x=expected_x,
y=expected_y,
z=expected_z,
unit='kpc',
representation_type='cartesian')
expected_xyz = expected.cartesian.xyz
# actual transformation to the frame
skyoffset_frame = SkyOffsetFrame(
origin=ICRS(ra * u.deg, dec * u.deg))
actual = icrs_coord.transform_to(skyoffset_frame)
actual_xyz = actual.cartesian.xyz
# back to ICRS
roundtrip = actual.transform_to(ICRS())
# Verify
assert_allclose(actual_xyz, expected_xyz, atol=1E-5 * u.kpc)
assert_allclose(icrs_coord.ra, roundtrip.ra, atol=1E-4 * u.deg)
assert_allclose(icrs_coord.dec, roundtrip.dec, atol=1E-5 * u.deg)
assert_allclose(icrs_coord.distance,
roundtrip.distance,
atol=1E-5 * u.kpc)
def test_skyoffset(inradec,
expectedlatlon,
tolsep,
originradec=(45, 45) * u.deg):
origin = ICRS(*originradec)
skyoffset_frame = SkyOffsetFrame(origin=origin)
skycoord = SkyCoord(*inradec, frame=ICRS)
skycoord_inaf = skycoord.transform_to(skyoffset_frame)
assert hasattr(skycoord_inaf, 'lon')
assert hasattr(skycoord_inaf, 'lat')
expected = SkyCoord(*expectedlatlon, frame=skyoffset_frame)
assert skycoord_inaf.separation(expected) < tolsep
def test_skyoffset(inradec, expectedlatlon, tolsep, originradec=(45, 45)*u.deg):
origin = ICRS(*originradec)
skyoffset_frame = SkyOffsetFrame(origin=origin)
skycoord = SkyCoord(*inradec, frame=ICRS)
skycoord_inaf = skycoord.transform_to(skyoffset_frame)
assert hasattr(skycoord_inaf, 'lon')
assert hasattr(skycoord_inaf, 'lat')
expected = SkyCoord(*expectedlatlon, frame=skyoffset_frame)
assert skycoord_inaf.separation(expected) < tolsep
# Check we can also transform back (regression test for gh-11254).
roundtrip = skycoord_inaf.transform_to(ICRS())
assert roundtrip.separation(skycoord) < 1*u.uas
def test_skyoffset(inradec,
expectedlatlon,
tolsep,
originradec=(45, 45) * u.deg):
origin = ICRS(*originradec)
skyoffset_frame = SkyOffsetFrame(origin=origin)
skycoord = SkyCoord(*inradec, frame=ICRS)
skycoord_inaf = skycoord.transform_to(skyoffset_frame)
assert hasattr(skycoord_inaf, 'lon')
assert hasattr(skycoord_inaf, 'lat')
expected = SkyCoord(*expectedlatlon, frame=skyoffset_frame)
assert skycoord_inaf.separation(expected) < tolsep
# Check we can also transform back (regression test for gh-11254).
try:
roundtrip = skycoord_inaf.transform_to(ICRS())
except AttributeError as err:
if 'to_geodetic' in str(err):
pytest.xfail('See Issue 11277')
else:
raise
else:
assert roundtrip.separation(skycoord) < 1 * u.uas
def test_skyoffset_origindata():
origin = ICRS()
with pytest.raises(ValueError):
SkyOffsetFrame(origin=origin)
def test_skyoffset_lonwrap():
origin = ICRS(45 * u.deg, 45 * u.deg)
sc = SkyCoord(190 * u.deg,
-45 * u.deg,
frame=SkyOffsetFrame(origin=origin))
assert sc.lon < 180 * u.deg