slaDcs2c -

SYNOPSYS

PARAMETERS

double a

double b

double *v

DESCRIPTION

  Spherical coordinates to direction cosines.

  (double precision)

Given

     a,b       double      spherical coordinates in radians
                           (RA,Dec), (long,lat) etc

Returned

     v         double[3]   x,y,z unit vector

  The spherical coordinates are longitude (+ve anticlockwise
  looking from the +ve latitude pole) and latitude.  The
  Cartesian coordinates are right handed, with the x axis
  at zero longitude and latitude, and the z axis at the
  +ve latitude pole.

  P.T.Wallace   Starlink   31 October 1993

SEE ALSO

• slalib.3