--- ray/src/gen/gencat.c	1993/06/04 15:08:46	2.1
+++ ray/src/gen/gencat.c	1993/08/02 14:23:02	2.2
@@ -30,6 +30,10 @@ static char SCCSid[] = "$SunId$ LBL";
 #include <stdio.h>
 #include <math.h>
 
+#ifdef  DCL_ATOF
+extern double  atof();
+#endif
+
 char  *cmtype, *cname;
 double z0, z1;
 double k, D;