NAME:
vxvyvz_to_vrpmllpmbb
PURPOSE:
Transform velocities in the rectangular Galactic coordinate frame to the spherical Galactic coordinate frame (can take vector inputs)
INPUT:
vx - velocity towards the Galactic Center (km/s)
vy - velocity in the direction of Galactic rotation (km/s)
vz - velocity towards the North Galactic Pole (km/s)
l - Galactic longitude
b - Galactic lattitude
d - distance (kpc)
XYZ - (bool) If True, then l,b,d is actually X,Y,Z (rectangular Galactic coordinates)
degree - (bool) if True, l and b are in degrees
OUTPUT:
(vr,pmll,pmbb) in (km/s,mas/yr,mas/yr); pmll = mu_l * cos(b)
For vector inputs [:,3]
HISTORY:
2009-10-24 - Written - Bovy (NYU)
2014-06-14 - Re-written w/ numpy functions for speed and w/ decorators for beauty - Bovy (IAS)