Index: src/backend/utils/adt/geo_ops.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/adt/geo_ops.c,v
retrieving revision 1.84
diff -u -r1.84 geo_ops.c
--- src/backend/utils/adt/geo_ops.c	12 May 2004 22:38:44 -0000	1.84
+++ src/backend/utils/adt/geo_ops.c	18 May 2004 18:59:40 -0000
@@ -1313,6 +1313,27 @@
  *---------------------------------------------------------*/
 
 Datum
+path_area(PG_FUNCTION_ARGS)
+{
+	PATH	*path = PG_GETARG_PATH_P(0);
+	double	area = 0.0;
+	int i,j;
+
+	if (!path->closed)
+		PG_RETURN_NULL();
+
+	for (i = 0; i < path->npts; i++) {
+		j = (i + 1) % path->npts;
+		area += path->p[i].x * path->p[j].y;
+		area -= path->p[i].y * path->p[j].x;
+	}
+
+	area *= 0.5;
+	PG_RETURN_FLOAT8(area < 0.0 ? -area : area);
+}
+
+
+Datum
 path_in(PG_FUNCTION_ARGS)
 {
 	char	   *str = PG_GETARG_CSTRING(0);
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/catalog/pg_proc.h,v
retrieving revision 1.329
diff -u -r1.329 pg_proc.h
--- src/include/catalog/pg_proc.h	14 May 2004 21:42:28 -0000	1.329
+++ src/include/catalog/pg_proc.h	18 May 2004 18:59:41 -0000
@@ -1259,6 +1259,8 @@
 DESCR("box height");
 DATA(insert OID = 978 (  box_distance	   PGNSP PGUID 12 f f t f i 2 701 "603 603" _null_  box_distance - _null_ ));
 DESCR("distance between boxes");
+DATA(insert OID = 979 (  area			   PGNSP PGUID 12 f f t f i 1 701 "602" _null_  path_area - _null_ ));
+DESCR("area of a closed path");
 DATA(insert OID = 980 (  box_intersect	   PGNSP PGUID 12 f f t f i 2 603 "603 603" _null_  box_intersect - _null_ ));
 DESCR("box intersection (another box)");
 DATA(insert OID = 981 (  diagonal		   PGNSP PGUID 12 f f t f i 1 601 "603" _null_  box_diagonal - _null_ ));
Index: src/include/utils/geo_decls.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/utils/geo_decls.h,v
retrieving revision 1.43
diff -u -r1.43 geo_decls.h
--- src/include/utils/geo_decls.h	29 Nov 2003 22:41:15 -0000	1.43
+++ src/include/utils/geo_decls.h	18 May 2004 18:59:41 -0000
@@ -305,6 +305,7 @@
 extern Datum box_div(PG_FUNCTION_ARGS);
 
 /* public path routines */
+extern Datum path_area(PG_FUNCTION_ARGS);
 extern Datum path_in(PG_FUNCTION_ARGS);
 extern Datum path_out(PG_FUNCTION_ARGS);
 extern Datum path_recv(PG_FUNCTION_ARGS);