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/f90/mod/pix_tools.f90


FORMAT

call vec2ang( vector, theta, phi )


ARGUMENTS

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

Eric Hivon 2003-02-07