healpy.rotator.Rotator.angle_ref

Rotator.angle_ref(*args, **kwds)

Compute the angle between transverse reference direction of initial and final frames

For example, if angle of polarisation is psi in initial frame, it will be psi+angle_ref in final frame.

Parameters:
dir_or_vecarray

Direction or vector (see Rotator.__call__)

lonlat: bool, optional

If True, assume input is longitude,latitude in degrees. Otherwise, theta,phi in radian. Default: False

invbool, optional

If True, use the inverse transforms. Default: False

Returns:
anglefloat, scalar or array

Angle in radian (a scalar or an array if input is a sequence of direction/vector)