Index: branches/pap/psphot/src/psphotDiagnosticPlots.c
===================================================================
--- branches/pap/psphot/src/psphotDiagnosticPlots.c	(revision 23948)
+++ branches/pap/psphot/src/psphotDiagnosticPlots.c	(revision 25027)
@@ -40,5 +40,8 @@
 
     psStats *stats = psStatsAlloc (PS_STAT_MAX | PS_STAT_MIN);
-    psVectorStats (stats, values, NULL, NULL, 0);
+    if (!psVectorStats (stats, values, NULL, NULL, 0)) {
+	psError(PS_ERR_UNKNOWN, false, "failure to measure stats for histogram");
+        return false;
+    }
 
     psHistogram *histogram = psHistogramAlloc (stats->min, stats->max, 1000);
@@ -63,5 +66,8 @@
     psStatsInit (stats);
     stats->options = PS_STAT_MAX | PS_STAT_MIN;
-    psVectorStats (stats, histogram->nums, NULL, NULL, 0);
+    if (!psVectorStats (stats, histogram->nums, NULL, NULL, 0)) {
+	psError(PS_ERR_UNKNOWN, false, "failure to measure stats for histogram");
+        return false;
+    }
 
     // scale the plot to hold the histogram
@@ -100,5 +106,8 @@
     psStatsInit (stats);
     stats->options = PS_STAT_MAX | PS_STAT_MIN;
-    psVectorStats (stats, histogram->nums, NULL, NULL, 0);
+    if (!psVectorStats (stats, histogram->nums, NULL, NULL, 0)) {
+	psError(PS_ERR_UNKNOWN, false, "failure to measure stats for histogram");
+        return false;
+    }
 
     // scale the plot to hold the histogram