--- ray/src/px/ra_skel.c	1992/09/21 12:15:17	2.3
+++ ray/src/px/ra_skel.c	1993/06/04 14:47:53	2.5
@@ -4,6 +4,8 @@
 static char SCCSid[] = "$SunId$ LBL";
 #endif
 
+/*
+ *  Skeletal 24-bit image conversion program.  Replace "skel"
  *  in this file with a more appropriate image type identifier.
  *
  *  The Makefile entry should look something like this:
@@ -17,6 +19,7 @@ static char SCCSid[] = "$SunId$ LBL";
  */
 
 #include  <stdio.h>
+#include  <math.h>
 #ifdef MSDOS
 #include  <fcntl.h>
 #endif