--- ray/src/util/eplus_adduvf.c	2014/02/10 04:51:26	2.3
+++ ray/src/util/eplus_adduvf.c	2014/02/10 17:50:02	2.4
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: eplus_adduvf.c,v 2.3 2014/02/10 04:51:26 greg Exp $";
+static const char RCSid[] = "$Id: eplus_adduvf.c,v 2.4 2014/02/10 17:50:02 greg Exp $";
 #endif
 /*
  * Add User View Factors to EnergyPlus Input Data File
@@ -305,7 +305,7 @@ sample_triangle(const Vert2_list *vl2, int a, int b, i
 	samp = (float *)malloc(sizeof(float)*6*ns);
 	if (samp == NULL)
 		return(0);
-	for (i = ns; i--; ) {
+	for (i = ns; i--; ) {		/* stratified Monte Carlo sampling */
 		double	sv[4];
 		multisamp(sv, 4, (i+frandom())/(double)ns);
 		sv[0] *= sv[1] = sqrt(sv[1]);
@@ -379,6 +379,7 @@ compute_uvfs(SUBPROC *pd, ZONE *zp)
 		return(0);
 						/* UVFs from each surface */
 	for (n = zp->nsurf, pptr = zp->pfirst; n--; pptr = pptr->dnext) {
+		double	vfsum = 0;
 						/* send samples to rcontrib */
 		if (!sample_surface(pptr, pd->w))
 			return(0);
@@ -392,6 +393,7 @@ compute_uvfs(SUBPROC *pd, ZONE *zp)
 						/* append UVF fields */
 		for (m = 0, pptr1 = zp->pfirst;
 				m < zp->nsurf; m++, pptr1 = pptr1->dnext) {
+			vfsum += uvfa[3*m + 1];
 			if (pptr1 == pptr) {
 				if (uvfa[3*m + 1] > .001)
 					fprintf(stderr,
@@ -413,6 +415,11 @@ compute_uvfs(SUBPROC *pd, ZONE *zp)
 				return(0);
 			}
 		}
+		if (vfsum < 0.95)
+			fprintf(stderr,
+		"%s: warning - missing %.1f%% of energy from surface '%s'\n",
+					progname, 100.*(1.-vfsum),
+					idf_getfield(pptr,NAME_FLD)->val);
 	}
 	free(uvfa);				/* clean up and return */
 	return(1);