NAME:
pmrapmdec_to_pmllpmbb
PURPOSE:
rotate proper motions in (ra,dec) into proper motions in (l,b)
INPUT:
pmra - proper motion in ra (multplied with cos(dec)) [mas/yr]
pmdec - proper motion in dec [mas/yr]
ra - right ascension
dec - declination
degree - if True, ra and dec are given in degrees (default=False)
epoch - epoch of ra,dec (right now only 2000.0 and 1950.0 are supported)
OUTPUT:
(pmll,pmbb) for vector inputs [:,2]
HISTORY:
2010-04-07 - Written - Bovy (NYU)
2014-06-14 - Re-written w/ numpy functions for speed and w/ decorators for beauty - Bovy (IAS)