--- ray/src/cv/bsdfrep.h	2014/02/19 05:16:06	2.12
+++ ray/src/cv/bsdfrep.h	2014/03/06 00:40:37	2.13
@@ -1,4 +1,4 @@
-/* RCSid $Id: bsdfrep.h,v 2.12 2014/02/19 05:16:06 greg Exp $ */
+/* RCSid $Id: bsdfrep.h,v 2.13 2014/03/06 00:40:37 greg Exp $ */
 /*
  * Definitions for BSDF representation used to interpolate measured data.
  *
@@ -106,7 +106,7 @@ extern MIGRATION	*mig_list;
 extern char		*progname;
 
 				/* get theta value in degrees [0,180) range */
-#define get_theta180(v)	((180./M_PI)*acos((v)[2]))
+#define get_theta180(v)	((180./M_PI)*Acos((v)[2]))
 				/* get phi value in degrees, [0,360) range */
 #define	get_phi360(v)	((180./M_PI)*atan2((v)[1],(v)[0]) + 360.*((v)[1]<0))