healpy.rotator.angdist(dir1, dir2, lonlat=False)

Returns the angular distance between dir1 and dir2.


dir1, dir2 : float, array-like

The directions between which computing the angular distance. Angular if len(dir) == 2 or vector if len(dir) == 3. See lonlat for unit

lonlat : bool, scalar or sequence

If True, angles are assumed to be longitude and latitude in degree, otherwise they are interpreted as colatitude and longitude in radian. If a sequence, lonlat[0] applies to dir1 and lonlat[1] applies to dir2.


angles : float, scalar or array-like

The angle(s) between dir1 and dir2 in radian.


>>> import healpy as hp
>>> hp.rotator.angdist([.2,0], [.2, 1e-6])
array([  1.98669331e-07])