def test_hcc_hgs_observer_mismatch():
# Test whether the transformation gives the same answer regardless of what obstime the observer
# coordinate is represented in
observer1 = HeliographicStonyhurst(0 * u.deg,
0 * u.deg,
1 * u.AU,
obstime='2001-01-01')
observer2 = observer1.transform_to(
HeliographicStonyhurst(obstime='2001-03-31'))
hcc1 = Heliocentric(0.2 * u.AU,
0.3 * u.AU,
0.4 * u.AU,
observer=observer1,
obstime=observer1.obstime)
hgs1 = hcc1.transform_to(HeliographicStonyhurst(obstime=hcc1.obstime))
hcc2 = Heliocentric(0.2 * u.AU,
0.3 * u.AU,
0.4 * u.AU,
observer=observer2,
obstime=observer1.obstime)
hgs2 = hcc2.transform_to(HeliographicStonyhurst(obstime=hcc2.obstime))
assert_quantity_allclose(hgs1.lon, hgs2.lon)
assert_quantity_allclose(hgs1.lat, hgs2.lat)
assert_quantity_allclose(hgs1.radius, hgs2.radius)
def test_hcc_hcc():
# Test same observer and changing obstime
observer = HeliographicStonyhurst(0 * u.deg,
0 * u.deg,
1 * u.AU,
obstime='2001-02-01')
from_hcc = Heliocentric(0.2 * u.AU,
0.3 * u.AU,
0.4 * u.AU,
observer=observer,
obstime='2001-01-01')
to_hcc = from_hcc.transform_to(
Heliocentric(observer=observer, obstime='2001-03-31'))
# Since the observer is the same, the coordinates should be nearly the same but not exactly
# equal due to motion of the origin (the Sun)
assert np.all(from_hcc.cartesian.xyz != to_hcc.cartesian.xyz)
assert_quantity_allclose(from_hcc.cartesian.xyz,
to_hcc.cartesian.xyz,
rtol=2e-3)
# Test changing observer and same obstime
observer1 = HeliographicStonyhurst(0 * u.deg,
0 * u.deg,
1 * u.AU,
obstime='2001-01-01')
observer2 = HeliographicStonyhurst(0 * u.deg,
0 * u.deg,
1 * u.AU,
obstime='2001-03-31')
from_hcc = Heliocentric(0.2 * u.AU,
0.3 * u.AU,
0.4 * u.AU,
observer=observer1,
obstime='2001-02-01')
to_hcc = from_hcc.transform_to(
Heliocentric(observer=observer2, obstime='2001-02-01'))
# This change in observer is approximately a 90-degree rotation about the Y axis
assert_quantity_allclose(to_hcc.x, -from_hcc.z, rtol=2e-3)
assert_quantity_allclose(to_hcc.y, from_hcc.y, rtol=2e-3)
assert_quantity_allclose(to_hcc.z, from_hcc.x, rtol=2e-3)
def test_hcc_to_hgs():
'''
Check that a coordinate pointing to the observer in Heliocentric
coordinates maps to the lattitude/longitude of the observer in
HeliographicStonyhurst coordinates.
'''
lat = 10 * u.deg
lon = 20 * u.deg
observer = HeliographicStonyhurst(lat=lat, lon=lon)
hcc_in = Heliocentric(x=0*u.km, y=0*u.km, z=1*u.km, observer=observer)
hgs_out = hcc_in.transform_to(HeliographicStonyhurst)
assert_quantity_allclose(hgs_out.lat, lat)
assert_quantity_allclose(hgs_out.lon, lon)
def test_hcc_to_hgs():
'''
Check that a coordinate pointing to the observer in Heliocentric
coordinates maps to the lattitude/longitude of the observer in
HeliographicStonyhurst coordinates.
'''
lat = 10 * u.deg
lon = 20 * u.deg
observer = HeliographicStonyhurst(lat=lat, lon=lon)
hcc_in = Heliocentric(x=0*u.km, y=0*u.km, z=1*u.km, observer=observer)
hgs_out = hcc_in.transform_to(HeliographicStonyhurst)
assert_quantity_allclose(hgs_out.lat, lat)
assert_quantity_allclose(hgs_out.lon, lon)
