slaDsep -

SYNOPSYS

double slaDsep(a1, b1, a2, b2)

PARAMETERS

double a1
double b1
double a2
double b2

DESCRIPTION


  Angle between two points on a sphere.

  (double precision)

Given

     a1,b1    double    spherical coordinates of one point
     a2,b2    double    spherical coordinates of the other point

  (The spherical coordinates are RA,dec, long,lat etc, in radians.)

  The result is the angle, in radians, between the two points.  It
  is always positive.

Called

 slaDcs2c

  P.T.Wallace   Starlink   31 October 1993

SEE ALSO