# Licensed under a 3-clause BSD style license - see LICENSE.rst

"""

Tests for the projected separation stuff

"""

import numpy as np

import pytest

from astropy import units as u

from astropy.coordinates import Angle

from astropy.coordinates.builtin_frames import ICRS

# lon1, lat1, lon2, lat2 in degrees

coords = [

(1, 0, 0, 0),

(0, 1, 0, 0),

(0, 0, 1, 0),

(0, 0, 0, 1),

(0, 0, 10, 0),

(0, 0, 90, 0),

(0, 0, 180, 0),

(0, 45, 0, -45),

(0, 60, 0, -30),

(-135, -15, 45, 15),

(100, -89, -80, 89),

(0, 0, 0, 0),

(0, 0, 1.0 / 60.0, 1.0 / 60.0),

]

correct_seps = [1, 1, 1, 1, 10, 90, 180, 90, 90, 180, 180, 0, 0.023570225877234643]

correctness_margin = 2e-10

def test_angsep():

"""

Tests that the angular separation object also behaves correctly.

"""

from astropy.coordinates import angular_separation

# check it both works with floats in radians, Quantities, or Angles

for conv in (np.deg2rad, lambda x: u.Quantity(x, "deg"), lambda x: Angle(x, "deg")):

for (lon1, lat1, lon2, lat2), corrsep in zip(coords, correct_seps):

angsep = angular_separation(conv(lon1), conv(lat1), conv(lon2), conv(lat2))

assert np.fabs(angsep - conv(corrsep)) < conv(correctness_margin)

def test_proj_separations():

"""

Test angular separation functionality

"""

c1 = ICRS(ra=0 * u.deg, dec=0 * u.deg)

c2 = ICRS(ra=0 * u.deg, dec=1 * u.deg)

# these operations have ambiguous interpretations for points on a sphere

with pytest.raises(TypeError):

c1 + c2

with pytest.raises(TypeError):

c1 - c2