class transfunc:
rep = r.CartesianRepresentation(np.arange(3)*u.pc)
dif = r.CartesianDifferential(*np.arange(3, 6)*u.pc/u.Myr)
rep0 = r.CartesianRepresentation(np.zeros(3)*u.pc)
@classmethod
def both(cls, coo, fr):
# exchange x <-> z and offset
M = np.array([[0., 0., 1.],
[0., 1., 0.],
[1., 0., 0.]])
return M, cls.rep.with_differentials(cls.dif)
@classmethod
def just_matrix(cls, coo, fr):
# exchange x <-> z and offset
M = np.array([[0., 0., 1.],
[0., 1., 0.],
[1., 0., 0.]])
return M, None
@classmethod
def no_matrix(cls, coo, fr):
return None, cls.rep.with_differentials(cls.dif)
@classmethod
def no_pos(cls, coo, fr):
return None, cls.rep0.with_differentials(cls.dif)
@classmethod
def no_vel(cls, coo, fr):
return None, cls.rep
def setup_class(self):
self.x = np.array([3., 5., 0.]) << u.m
self.y = np.array([4., 12., 1.]) << u.m
self.z = np.array([0., 0., 1.]) << u.m
self.c = r.CartesianRepresentation(self.x, self.y, self.z)
self.mask = np.array([False, False, True])
self.mx = Masked(self.x, self.mask)
self.my = Masked(self.y, self.mask)
self.mz = Masked(self.z, self.mask)
self.mc = r.CartesianRepresentation(self.mx, self.my, self.mz)
def test_concatenate_representations_different_units():
from astropy.coordinates.funcs import concatenate_representations
from astropy.coordinates import representation as r
reps = [r.CartesianRepresentation([1, 2, 3.]*u.pc),
r.CartesianRepresentation([1, 2, 3.]*u.kpc)]
concat = concatenate_representations(reps)
assert concat.shape == (2,)
assert np.all(concat.xyz ==
([[1., 2., 3.], [1000., 2000., 3000.]] * u.pc).T)
def test_transform_decos():
"""
Tests the decorator syntax for creating transforms
"""
c1 = TCoo1(ra=1*u.deg, dec=2*u.deg)
@frame_transform_graph.transform(t.FunctionTransform, TCoo1, TCoo2)
def trans(coo1, f):
return TCoo2(ra=coo1.ra, dec=coo1.dec * 2)
c2 = c1.transform_to(TCoo2())
assert_allclose(c2.ra.degree, 1)
assert_allclose(c2.dec.degree, 4)
c3 = TCoo1(r.CartesianRepresentation(x=1*u.pc, y=1*u.pc, z=2*u.pc))
@frame_transform_graph.transform(t.StaticMatrixTransform, TCoo1, TCoo2)
def matrix():
return [[2, 0, 0],
[0, 1, 0],
[0, 0, 1]]
c4 = c3.transform_to(TCoo2())
assert_allclose(c4.cartesian.x, 2*u.pc)
assert_allclose(c4.cartesian.y, 1*u.pc)
assert_allclose(c4.cartesian.z, 2*u.pc)
def test_vel_transformation_obstime_err():
# TODO: replace after a final decision on PR #6280
from astropy.coordinates.sites import get_builtin_sites
diff = r.CartesianDifferential([.1, .2, .3]*u.km/u.s)
rep = r.CartesianRepresentation([1, 2, 3]*u.au, differentials=diff)
loc = get_builtin_sites()['example_site']
aaf = AltAz(obstime='J2010', location=loc)
aaf2 = AltAz(obstime=aaf.obstime + 3*u.day, location=loc)
aaf3 = AltAz(obstime=aaf.obstime + np.arange(3)*u.day, location=loc)
aaf4 = AltAz(obstime=aaf.obstime, location=loc)
aa = aaf.realize_frame(rep)
with pytest.raises(NotImplementedError) as exc:
aa.transform_to(aaf2)
assert 'cannot transform' in exc.value.args[0]
with pytest.raises(NotImplementedError) as exc:
aa.transform_to(aaf3)
assert 'cannot transform' in exc.value.args[0]
aa.transform_to(aaf4)
aa.transform_to(ICRS())
def lsr_to_icrs(lsr_coord, icrs_frame):
v_bary_gal = Galactic(lsr_coord.v_bary.to_cartesian())
v_bary_icrs = v_bary_gal.transform_to(icrs_frame)
v_offset = v_bary_icrs.data.represent_as(r.CartesianDifferential)
offset = r.CartesianRepresentation([0, 0, 0] * u.au,
differentials=-v_offset)
return None, offset
def test_representation_with_multiple_differentials():
from astropy.coordinates.builtin_frames import ICRS
dif1 = r.CartesianDifferential([1, 2, 3]*u.km/u.s)
dif2 = r.CartesianDifferential([1, 2, 3]*u.km/u.s**2)
rep = r.CartesianRepresentation([1, 2, 3]*u.pc,
differentials={'s': dif1, 's2': dif2})
# check warning is raised for a scalar
with pytest.raises(ValueError):
ICRS(rep)
def test_affine_transform_fail(transfunc):
diff = r.CartesianDifferential(8, 9, 10, unit=u.pc/u.Myr)
rep = r.CartesianRepresentation(5, 6, 7, unit=u.pc, differentials=diff)
c = TCoo1(rep)
# register and do the transformation and check against expected
trans = t.AffineTransform(transfunc, TCoo1, TCoo2)
trans.register(frame_transform_graph)
with pytest.raises(ValueError):
c.transform_to(TCoo2())
trans.unregister(frame_transform_graph)
def _get_matrix_vectors(gal_frame, inverse=False):
"""
Utility function: use the ``inverse`` argument to get the inverse transformation, matrix and
offsets to go from external galaxy frame to ICRS.
"""
# this is based on the astropy Galactocentric class code
# shorthand
gcf = gal_frame
# rotation matrix to align x(ICRS) with the vector to the galaxy center
mat0 = np.array([[0., 1., 0.],
[0., 0., 1.],
[1., 0., 0.]]) # relabel axes so x points in RA, y in dec, z away from us
mat1 = rotation_matrix(-gcf.gal_coord.dec, 'y')
mat2 = rotation_matrix(gcf.gal_coord.ra, 'z')
# construct transformation matrix and use it
R = matrix_product(mat0, mat1, mat2)
# Now define translation by distance to galaxy center - best defined in current sky coord system defined by R
translation = r.CartesianRepresentation(gcf.gal_distance * [0., 0., 1.])
# Now rotate galaxy to right orientation
pa_rot = rotation_matrix(-gcf.PA, 'z')
inc_rot = rotation_matrix(gcf.inclination, 'y')
H = matrix_product(inc_rot, pa_rot)
# compute total matrices
A = matrix_product(H, R)
# Now we transform the translation vector between sky-aligned and galaxy-aligned frames
offset = -translation.transform(H)
if inverse:
# the inverse of a rotation matrix is a transpose, which is much faster
# and more stable to compute
A = matrix_transpose(A)
offset = (-offset).transform(A)
# galvel is given in sky-aligned coords, need to transform to ICRS, so use R transpose
R = matrix_transpose(R)
offset_v = r.CartesianDifferential.from_cartesian(
(gcf.galvel_heliocentric).to_cartesian().transform(R))
offset = offset.with_differentials(offset_v)
else:
# galvel is given in sky-aligned coords, need to transform to gal frame, so use H
offset_v = r.CartesianDifferential.from_cartesian(
(-gcf.galvel_heliocentric).to_cartesian().transform(H))
offset = offset.with_differentials(offset_v)
return A, offset
def test_shorthand_representations():
from astropy.coordinates.builtin_frames import ICRS
rep = r.CartesianRepresentation([1, 2, 3] * u.pc)
dif = r.CartesianDifferential([1, 2, 3] * u.km / u.s)
rep = rep.with_differentials(dif)
icrs = ICRS(rep)
sph = icrs.spherical
assert isinstance(sph, r.SphericalRepresentation)
assert isinstance(sph.differentials['s'], r.SphericalDifferential)
sph = icrs.sphericalcoslat
assert isinstance(sph, r.SphericalRepresentation)
assert isinstance(sph.differentials['s'], r.SphericalCosLatDifferential)
def get_matrix_vectors(galactocentric_frame, inverse=False):
"""
Use the ``inverse`` argument to get the inverse transformation, matrix and
offsets to go from Galactocentric to ICRS.
"""
# shorthand
gcf = galactocentric_frame
# rotation matrix to align x(ICRS) with the vector to the Galactic center
mat1 = rotation_matrix(-gcf.galcen_coord.dec, 'y')
mat2 = rotation_matrix(gcf.galcen_coord.ra, 'z')
# extra roll away from the Galactic x-z plane
mat0 = rotation_matrix(gcf.get_roll0() - gcf.roll, 'x')
# construct transformation matrix and use it
R = matrix_product(mat0, mat1, mat2)
# Now need to translate by Sun-Galactic center distance around x' and
# rotate about y' to account for tilt due to Sun's height above the plane
translation = r.CartesianRepresentation(gcf.galcen_distance * [1., 0., 0.])
z_d = gcf.z_sun / gcf.galcen_distance
H = rotation_matrix(-np.arcsin(z_d), 'y')
# compute total matrices
A = matrix_product(H, R)
# Now we re-align the translation vector to account for the Sun's height
# above the midplane
offset = -translation.transform(H)
if inverse:
# the inverse of a rotation matrix is a transpose, which is much faster
# and more stable to compute
A = matrix_transpose(A)
offset = (-offset).transform(A)
offset_v = r.CartesianDifferential.from_cartesian(
(-gcf.galcen_v_sun).to_cartesian().transform(A))
offset = offset.with_differentials(offset_v)
else:
offset = offset.with_differentials(gcf.galcen_v_sun)
return A, offset
def test_too_many_differentials():
dif1 = r.CartesianDifferential(*np.arange(3, 6)*u.pc/u.Myr)
dif2 = r.CartesianDifferential(*np.arange(3, 6)*u.pc/u.Myr**2)
rep = r.CartesianRepresentation(np.arange(3)*u.pc,
differentials={'s': dif1, 's2': dif2})
with pytest.raises(ValueError):
c = TCoo1(rep)
# register and do the transformation and check against expected
trans = t.AffineTransform(transfunc.both, TCoo1, TCoo2)
trans.register(frame_transform_graph)
# Check that if frame somehow gets through to transformation, multiple
# differentials are caught
c = TCoo1(rep.without_differentials())
c._data = c._data.with_differentials({'s': dif1, 's2': dif2})
with pytest.raises(ValueError):
c.transform_to(TCoo2())
trans.unregister(frame_transform_graph)
def galacticlsr_to_galactic(lsr_coord, galactic_frame):
v_bary_gal = Galactic(lsr_coord.v_bary.to_cartesian())
v_offset = v_bary_gal.data.represent_as(r.CartesianDifferential)
offset = r.CartesianRepresentation([0, 0, 0]*u.au, differentials=-v_offset)
return None, offset
peculiar motion of the sun relative to the LSRK.
"""
# NOTE: To avoid a performance penalty at import time, we hard-code the ICRS
# offsets here. The code to generate the offsets is provided for reproducibility.
# GORDON1975_V_BARY = 20*u.km/u.s
# GORDON1975_DIRECTION = FK4(ra=270*u.deg, dec=30*u.deg, equinox='B1900')
# V_OFFSET_LSRK = ((GORDON1975_V_BARY * GORDON1975_DIRECTION.transform_to(ICRS()).data)
# .represent_as(r.CartesianDifferential))
V_OFFSET_LSRK = r.CartesianDifferential([0.28999706839034606,
-17.317264789717928,
10.00141199546947]*u.km/u.s)
ICRS_LSRK_OFFSET = r.CartesianRepresentation([0, 0, 0]*u.au, differentials=V_OFFSET_LSRK)
LSRK_ICRS_OFFSET = r.CartesianRepresentation([0, 0, 0]*u.au, differentials=-V_OFFSET_LSRK)
@frame_transform_graph.transform(AffineTransform, ICRS, LSRK)
def icrs_to_lsrk(icrs_coord, lsr_frame):
return None, ICRS_LSRK_OFFSET
@frame_transform_graph.transform(AffineTransform, LSRK, ICRS)
def lsrk_to_icrs(lsr_coord, icrs_frame):
return None, LSRK_ICRS_OFFSET
# ------------------------------------------------------------------------------
return None, cls.rep.with_differentials(cls.dif)
@classmethod
def no_pos(cls, coo, fr):
return None, cls.rep0.with_differentials(cls.dif)
@classmethod
def no_vel(cls, coo, fr):
return None, cls.rep
@pytest.mark.parametrize('transfunc', [transfunc.both, transfunc.no_matrix,
transfunc.no_pos, transfunc.no_vel,
transfunc.just_matrix])
@pytest.mark.parametrize('rep', [
r.CartesianRepresentation(5, 6, 7, unit=u.pc),
r.CartesianRepresentation(5, 6, 7, unit=u.pc,
differentials=r.CartesianDifferential(8, 9, 10,
unit=u.pc/u.Myr)),
r.CartesianRepresentation(5, 6, 7, unit=u.pc,
differentials=r.CartesianDifferential(8, 9, 10,
unit=u.pc/u.Myr))
.represent_as(r.CylindricalRepresentation, r.CylindricalDifferential)
])
def test_affine_transform_succeed(transfunc, rep):
c = TCoo1(rep)
# compute expected output
M, offset = transfunc(c, TCoo2)
_rep = rep.to_cartesian()
@classmethod
def no_pos(cls, coo, fr):
return None, cls.rep0.with_differentials(cls.dif)
@classmethod
def no_vel(cls, coo, fr):
return None, cls.rep
@pytest.mark.parametrize('transfunc', [
transfunc.both, transfunc.no_matrix, transfunc.no_pos, transfunc.no_vel,
transfunc.just_matrix
])
@pytest.mark.parametrize('rep', [
r.CartesianRepresentation(5, 6, 7, unit=u.pc),
r.CartesianRepresentation(5,
6,
7,
unit=u.pc,
differentials=r.CartesianDifferential(
8, 9, 10, unit=u.pc / u.Myr)),
r.CartesianRepresentation(5,
6,
7,
unit=u.pc,
differentials=r.CartesianDifferential(
8, 9, 10, unit=u.pc / u.Myr)).represent_as(
r.CylindricalRepresentation,
r.CylindricalDifferential)
])
def test_concatenate_representations():
from astropy.coordinates.funcs import concatenate_representations
from astropy.coordinates import representation as r
reps = [r.CartesianRepresentation([1, 2, 3.]*u.kpc),
r.SphericalRepresentation(lon=1*u.deg, lat=2.*u.deg,
distance=10*u.pc),
r.UnitSphericalRepresentation(lon=1*u.deg, lat=2.*u.deg),
r.CartesianRepresentation(np.ones((3, 100)) * u.kpc),
r.CartesianRepresentation(np.ones((3, 16, 8)) * u.kpc)]
reps.append(reps[0].with_differentials(
r.CartesianDifferential([1, 2, 3.] * u.km/u.s)))
reps.append(reps[1].with_differentials(
r.SphericalCosLatDifferential(1*u.mas/u.yr, 2*u.mas/u.yr, 3*u.km/u.s)))
reps.append(reps[2].with_differentials(
r.SphericalCosLatDifferential(1*u.mas/u.yr, 2*u.mas/u.yr, 3*u.km/u.s)))
reps.append(reps[2].with_differentials(
r.UnitSphericalCosLatDifferential(1*u.mas/u.yr, 2*u.mas/u.yr)))
reps.append(reps[2].with_differentials(
{'s': r.RadialDifferential(1*u.km/u.s)}))
reps.append(reps[3].with_differentials(
r.CartesianDifferential(*np.ones((3, 100)) * u.km/u.s)))
reps.append(reps[4].with_differentials(
r.CartesianDifferential(*np.ones((3, 16, 8)) * u.km/u.s)))
# Test that combining all of the above with itself succeeds
for rep in reps:
if not rep.shape:
expected_shape = (2, )
else:
expected_shape = (2 * rep.shape[0], ) + rep.shape[1:]
tmp = concatenate_representations((rep, rep))
assert tmp.shape == expected_shape
if 's' in rep.differentials:
assert tmp.differentials['s'].shape == expected_shape
# Try combining 4, just for something different
for rep in reps:
if not rep.shape:
expected_shape = (4, )
else:
expected_shape = (4 * rep.shape[0], ) + rep.shape[1:]
tmp = concatenate_representations((rep, rep, rep, rep))
assert tmp.shape == expected_shape
if 's' in rep.differentials:
assert tmp.differentials['s'].shape == expected_shape
# Test that combining pairs fails
with pytest.raises(TypeError):
concatenate_representations((reps[0], reps[1]))
with pytest.raises(ValueError):
concatenate_representations((reps[0], reps[5]))
# Check that passing in a single object fails
with pytest.raises(TypeError):
concatenate_representations(reps[0])
