def test_inv():
ell = Ellipsoid('WGS84')
# check meridian arc
np.testing.assert_almost_equal(ell.meridian_arc_distance(0.0, 90),
ell.quadrant_distance,
decimal=4)
# check equatorial circle
circle_length = 2 * np.pi * ell.a
np.testing.assert_almost_equal(ell.parallel_arc_distance(0.0, 0.0, 90.),
circle_length / 4,
decimal=5)
# Load short test data from Geographiclib
# https://geographiclib.sourceforge.io/html/geodesic.html#testgeod
path = os.path.dirname(os.path.abspath(__file__))
fname = os.path.join(path, 'data/GeodTest-short.dat.gz')
(lat1, lon1, azi1, lat2, lon2, azi2,
dist12) = np.loadtxt(fname,
usecols=(0, 1, 2, 3, 4, 5, 6),
unpack=True,
dtype=np.float64)
b_azi1, b_azi2, b_dist12 = ell.inv(lat1, lon1, lat2, lon2)
# NOTE: Loss of precision
np.testing.assert_array_almost_equal(b_azi1, azi1, decimal=3)
np.testing.assert_array_almost_equal(b_azi2, azi2 - 180., decimal=3)
np.testing.assert_array_almost_equal(b_dist12, dist12, decimal=8)
def test_latitude_dependend_values():
# From
# Deakin, R.E. and Hunter, M.N., 2010. Geometric geodesy part A. Lecture
# Notes, School of Mathematical & Geospatial Sciences, RMIT University,
# Melbourne, Australia.
# pp. 87 - 88
ell = Ellipsoid('GRS80')
lat = -(37 + 48 / 60 + 33.1234 / 3600) * u.deg
np.testing.assert_almost_equal(ell._w(lat).value, 0.998741298, decimal=9)
np.testing.assert_almost_equal(ell._v(lat).value, 1.002101154, decimal=9)
np.testing.assert_almost_equal(ell.meridian_curvature_radius(lat).value,
6359422.962,
decimal=3)
np.testing.assert_almost_equal(
ell.prime_vertical_curvature_radius(lat).value, 6386175.289, decimal=3)
np.testing.assert_almost_equal(ell.mean_curvature(lat).value,
1 / 6372785.088,
decimal=16)
np.testing.assert_almost_equal(ell.meridian_arc_distance(0.0 * u.deg,
lat).value,
4186320.340,
decimal=3)