galpy.util.coords.vxvyvz_to_vrpmllpmbb¶
- galpy.util.coords.vxvyvz_to_vrpmllpmbb(vx, vy, vz, l, b, d, XYZ=False, degree=False)[source]¶
Transform velocities in the rectangular Galactic coordinate frame to the spherical Galactic coordinate frame (can take vector inputs)
- Parameters:
vx (float or numpy.ndarray) – Velocity towards the Galactic Center (km/s)
vy (float or numpy.ndarray) – Velocity in the direction of Galactic rotation (km/s)
vz (float or numpy.ndarray) – Velocity towards the North Galactic Pole (km/s)
l (float or numpy.ndarray) – Galactic longitude
b (float or numpy.ndarray) – Galactic latitude
d (float or numpy.ndarray) – Distance (kpc)
XYZ (bool, optional) – If True, then l,b,d is actually X,Y,Z (rectangular Galactic coordinates). Default is False.
degree (bool, optional) – If True, l and b are in degrees. Default is False.
- Returns:
[vr,pmll x cos(b),pmbb] in (km/s,mas/yr,mas/yr). For vector inputs [:,3]
- Return type:
tuple or numpy.ndarray
Notes
2009-10-24 - Written - Bovy (NYU)
2014-06-14 - Re-written w/ numpy functions for speed and w/ decorators for beauty - Bovy (IAS)