--- ray/src/common/linregr.h	1991/11/12 16:55:45	2.1
+++ ray/src/common/linregr.h	2003/06/27 06:53:21	2.6
@@ -1,10 +1,12 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
-/* SCCSid "$SunId$ LBL" */
-
+/* RCSid $Id: linregr.h,v 2.6 2003/06/27 06:53:21 greg Exp $ */
 /*
  * Header file for linear regression calculation.
  */
+#ifndef _RAD_LINEGR_H_
+#define _RAD_LINEGR_H_
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 typedef struct {
 	double	xs, ys, xxs, yys, xys;
@@ -15,8 +17,6 @@ typedef struct {
 	double	slope, intercept, correlation;
 } LRLIN;
 
-extern double	sqrt();
-
 #define	lrpoint(x,y,l)	((l)->xs+=(x),(l)->ys+=(y),(l)->xxs+=(x)*(x), \
 			(l)->yys+=(y)*(y),(l)->xys+=(x)*(y),++(l)->n)
 
@@ -26,3 +26,15 @@ extern double	sqrt();
 #define	lryvar(l)	(((l)->yys-(l)->ys*(l)->ys/(l)->n)/(l)->n)
 #define	lrxdev(l)	sqrt(((l)->xxs-(l)->xs*(l)->xs/(l)->n)/((l)->n-1))
 #define	lrydev(l)	sqrt(((l)->yys-(l)->ys*(l)->ys/(l)->n)/((l)->n-1))
+
+
+extern void	lrclear(LRSUM *l);
+extern int	flrpoint(double x, double y, LRSUM *l);
+extern int	lrfit(LRLIN *r, LRSUM *l);
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _RAD_LINEGR_H_ */
+