def test_from_icrs(self):
# scalar positions
transformed = self.sun_icrs_scalar.transform_to(HCRS(obstime=self.t1))
separation = transformed.separation_3d(self.sun_hcrs_t1)
assert_allclose(separation, 0*u.km, atol=self.tolerance)
# nonscalar positions
transformed = self.sun_icrs_arr.transform_to(HCRS(obstime=self.tarr))
separation = transformed.separation_3d(self.sun_hcrs_tarr)
assert_allclose(separation, 0*u.km, atol=self.tolerance)
class TestHCRS():
"""
Check HCRS<->ICRS coordinate conversions.
Uses ICRS Solar positions predicted by get_body_barycentric; with `t1` and
`tarr` as defined below, the ICRS Solar positions were predicted using, e.g.
coord.ICRS(coord.get_body_barycentric(tarr, 'sun')).
"""
def setup(self):
self.t1 = Time("2013-02-02T23:00")
self.t2 = Time("2013-08-02T23:00")
self.tarr = Time(["2013-02-02T23:00", "2013-08-02T23:00"])
self.sun_icrs_scalar = ICRS(ra=244.52984668 * u.deg,
dec=-22.36943723 * u.deg,
distance=406615.66347377 * u.km)
# array of positions corresponds to times in `tarr`
self.sun_icrs_arr = ICRS(ra=[244.52989062, 271.40976248] * u.deg,
dec=[-22.36943605, -25.07431079] * u.deg,
distance=[406615.66347377, 375484.13558956] *
u.km)
# corresponding HCRS positions
self.sun_hcrs_t1 = HCRS(CartesianRepresentation([0.0, 0.0, 0.0] *
u.km),
obstime=self.t1)
twod_rep = CartesianRepresentation(
[[0.0, 0.0], [0.0, 0.0], [0.0, 0.0]] * u.km)
self.sun_hcrs_tarr = HCRS(twod_rep, obstime=self.tarr)
self.tolerance = 5 * u.km
def test_from_hcrs(self):
# test scalar transform
transformed = self.sun_hcrs_t1.transform_to(ICRS())
separation = transformed.separation_3d(self.sun_icrs_scalar)
assert_allclose(separation, 0 * u.km, atol=self.tolerance)
# test non-scalar positions and times
transformed = self.sun_hcrs_tarr.transform_to(ICRS())
separation = transformed.separation_3d(self.sun_icrs_arr)
assert_allclose(separation, 0 * u.km, atol=self.tolerance)
def test_from_icrs(self):
# scalar positions
transformed = self.sun_icrs_scalar.transform_to(HCRS(obstime=self.t1))
separation = transformed.separation_3d(self.sun_hcrs_t1)
assert_allclose(separation, 0 * u.km, atol=self.tolerance)
# nonscalar positions
transformed = self.sun_icrs_arr.transform_to(HCRS(obstime=self.tarr))
separation = transformed.separation_3d(self.sun_hcrs_tarr)
assert_allclose(separation, 0 * u.km, atol=self.tolerance)
class TestHCRS():
"""
Check HCRS<->ICRS coordinate conversions.
Uses ICRS Solar positions predicted by get_body_barycentric; with `t1` and
`tarr` as defined below, the ICRS Solar positions were predicted using, e.g.
coord.ICRS(coord.get_body_barycentric(tarr, 'sun')).
"""
def setup(self):
self.t1 = Time("2013-02-02T23:00")
self.t2 = Time("2013-08-02T23:00")
self.tarr = Time(["2013-02-02T23:00", "2013-08-02T23:00"])
self.sun_icrs_scalar = ICRS(ra=244.52984668*u.deg,
dec=-22.36943723*u.deg,
distance=406615.66347377*u.km)
# array of positions corresponds to times in `tarr`
self.sun_icrs_arr = ICRS(ra=[244.52989062, 271.40976248]*u.deg,
dec=[-22.36943605, -25.07431079]*u.deg,
distance=[406615.66347377, 375484.13558956]*u.km)
# corresponding HCRS positions
self.sun_hcrs_t1 = HCRS(CartesianRepresentation([0.0, 0.0, 0.0] * u.km),
obstime=self.t1)
twod_rep = CartesianRepresentation([[0.0, 0.0], [0.0, 0.0], [0.0, 0.0]] * u.km)
self.sun_hcrs_tarr = HCRS(twod_rep, obstime=self.tarr)
self.tolerance = 5*u.km
def test_from_hcrs(self):
# test scalar transform
transformed = self.sun_hcrs_t1.transform_to(ICRS())
separation = transformed.separation_3d(self.sun_icrs_scalar)
assert_allclose(separation, 0*u.km, atol=self.tolerance)
# test non-scalar positions and times
transformed = self.sun_hcrs_tarr.transform_to(ICRS())
separation = transformed.separation_3d(self.sun_icrs_arr)
assert_allclose(separation, 0*u.km, atol=self.tolerance)
def test_from_icrs(self):
# scalar positions
transformed = self.sun_icrs_scalar.transform_to(HCRS(obstime=self.t1))
separation = transformed.separation_3d(self.sun_hcrs_t1)
assert_allclose(separation, 0*u.km, atol=self.tolerance)
# nonscalar positions
transformed = self.sun_icrs_arr.transform_to(HCRS(obstime=self.tarr))
separation = transformed.separation_3d(self.sun_hcrs_tarr)
assert_allclose(separation, 0*u.km, atol=self.tolerance)
def test_hcrs_icrs_differentials():
# Regression to ensure that we can transform velocities from HCRS to LSR.
# Numbers taken from the original issue, gh-6835.
hcrs = HCRS(ra=8.67*u.deg, dec=53.09*u.deg, distance=117*u.pc,
pm_ra_cosdec=4.8*u.mas/u.yr, pm_dec=-15.16*u.mas/u.yr,
radial_velocity=23.42*u.km/u.s)
icrs = hcrs.transform_to(ICRS)
# The position and velocity should not change much
assert allclose(hcrs.cartesian.xyz, icrs.cartesian.xyz, rtol=1e-8)
assert allclose(hcrs.velocity.d_xyz, icrs.velocity.d_xyz, rtol=1e-2)
hcrs2 = icrs.transform_to(HCRS)
# The values should round trip
assert allclose(hcrs.cartesian.xyz, hcrs2.cartesian.xyz, rtol=1e-12)
assert allclose(hcrs.velocity.d_xyz, hcrs2.velocity.d_xyz, rtol=1e-12)
def setup(self):
self.t1 = Time("2013-02-02T23:00")
self.t2 = Time("2013-08-02T23:00")
self.tarr = Time(["2013-02-02T23:00", "2013-08-02T23:00"])
self.sun_icrs_scalar = ICRS(ra=244.52984668*u.deg,
dec=-22.36943723*u.deg,
distance=406615.66347377*u.km)
# array of positions corresponds to times in `tarr`
self.sun_icrs_arr = ICRS(ra=[244.52989062, 271.40976248]*u.deg,
dec=[-22.36943605, -25.07431079]*u.deg,
distance=[406615.66347377, 375484.13558956]*u.km)
# corresponding HCRS positions
self.sun_hcrs_t1 = HCRS(CartesianRepresentation([0.0, 0.0, 0.0] * u.km),
obstime=self.t1)
twod_rep = CartesianRepresentation([[0.0, 0.0], [0.0, 0.0], [0.0, 0.0]] * u.km)
self.sun_hcrs_tarr = HCRS(twod_rep, obstime=self.tarr)
self.tolerance = 5*u.km
def setup(self):
self.t1 = Time("2013-02-02T23:00")
self.t2 = Time("2013-08-02T23:00")
self.tarr = Time(["2013-02-02T23:00", "2013-08-02T23:00"])
self.sun_icrs_scalar = ICRS(ra=244.52984668*u.deg,
dec=-22.36943723*u.deg,
distance=406615.66347377*u.km)
# array of positions corresponds to times in `tarr`
self.sun_icrs_arr = ICRS(ra=[244.52989062, 271.40976248]*u.deg,
dec=[-22.36943605, -25.07431079]*u.deg,
distance=[406615.66347377, 375484.13558956]*u.km)
# corresponding HCRS positions
self.sun_hcrs_t1 = HCRS(CartesianRepresentation([0.0, 0.0, 0.0] * u.km),
obstime=self.t1)
twod_rep = CartesianRepresentation([[0.0, 0.0], [0.0, 0.0], [0.0, 0.0]] * u.km)
self.sun_hcrs_tarr = HCRS(twod_rep, obstime=self.tarr)
self.tolerance = 5*u.km
def test_heliocentric(self):
gcrs = self.wht_itrs.transform_to(GCRS(obstime=self.obstime))
helio = gcrs.transform_to(HCRS(obstime=self.obstime))
# Check it doesn't change from previous times.
previous = [-1.02597256e+11, 9.71725820e+10, 4.21268419e+10] * u.m
assert_allclose(helio.cartesian.xyz, previous)
# And that it agrees with SLALIB to within 14km
helio_slalib = [-0.685820296, 0.6495585893, 0.2816005464] * u.au
assert np.sqrt(((helio.cartesian.xyz -
helio_slalib)**2).sum()) < 14. * u.km
