def cyl_to_rect_vec(vr,vt,vz,phi):
    """
    NAME:

       cyl_to_rect_vec

    PURPOSE:

       transform vectors from cylindrical to rectangular coordinate vectors

    INPUT:

       vr - radial velocity

       vt - tangential velocity

       vz - vertical velocity

       phi - azimuth

    OUTPUT:

       vx,vy,vz

    HISTORY:

       2011-02-24 - Written - Bovy (NYU)

    """
    vx= vr*sc.cos(phi)-vt*sc.sin(phi)
    vy= vr*sc.sin(phi)+vt*sc.cos(phi)
    return (vx,vy,vz)
def cyl_to_rect_vec ( vr , vt , vz , phi ) : vx = vr * sc . cos ( phi ) - vt * sc . sin ( phi ) vy = vr * sc . sin ( phi ) + vt * sc . cos ( phi ) return ( vx , vy , vz )
NAME:

       cyl_to_rect_vec

    PURPOSE:

       transform vectors from cylindrical to rectangular coordinate vectors

    INPUT:

       vr - radial velocity

       vt - tangential velocity

       vz - vertical velocity

       phi - azimuth

    OUTPUT:

       vx,vy,vz

    HISTORY:

       2011-02-24 - Written - Bovy (NYU)