vec2ang

Routine to convert the 3D position vector (x,y,z) of point into its position angles $(\theta,\phi) $ on the sphere with $x = \sin\theta\cos\phi $, $y=\sin\theta\sin\phi $, $z=\cos\theta $.

Location in HEALPix directory tree: src/C/subs/chealpix.c 


FORMAT

void vec2ang(double *vector, double *theta, double *phi);


ARGUMENTS

name & dimensionality kind in/out description
       
vector(3) double IN three dimensional cartesian position vector (x,y,z). The north pole is (0,0,1)
theta double OUT colatitude in radians measured southward from north pole (in [0,$\pi$]).
phi double OUT longitude in radians measured eastward (in [0, $2\pi$]).


RELATED ROUTINES

This section lists the routines related to vec2ang

ang2vec
converts the position angles of a point on the sphere into its 3D position vector.

Version 3.82, 2022-07-28