#! /bin/bash
#R. Stiening June 14, 2006
#Select distance(a.ra,a.decl,b.ra,b.decl) RETURNS great circle distance between a and b in arc-seconds
psql -ec "CREATE OR REPLACE FUNCTION distance(float,float,float,float)
         RETURNS float AS
         'SELECT
	 7200.0*degrees
         (
	 asin
	 (
	 sqrt((sin(0.5*radians(\$2-\$4)))^2 +
         cos(radians(\$2))*cos(radians(\$4))*(sin(0.5*radians(\$1-\$3)))^2)
         )
	 )'
	 LANGUAGE SQL IMMUTABLE RETURNS NULL ON NULL INPUT;
        " wsdb