Index: trunk/Ohana/src/opihi/cmd.data/zplot.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/zplot.c	(revision 2843)
+++ trunk/Ohana/src/opihi/cmd.data/zplot.c	(revision 7917)
@@ -18,5 +18,5 @@
 
   if (argc != 6) {
-    fprintf (stderr, "USAGE: zplot <x> <y> <z> min max\n");
+    gprint (GP_ERR, "USAGE: zplot <x> <y> <z> min max\n");
     return (FALSE);
   }
@@ -30,9 +30,9 @@
   if ((zvec = SelectVector (argv[3], OLDVECTOR, TRUE)) == NULL) return (FALSE);
   if (xvec[0].Nelements != yvec[0].Nelements) {
-    fprintf (stderr, "vectors %s and %s not the same length\n", argv[1], argv[2]);
+    gprint (GP_ERR, "vectors %s and %s not the same length\n", argv[1], argv[2]);
     return (FALSE);
   }
   if (xvec[0].Nelements != zvec[0].Nelements) {
-    fprintf (stderr, "vectors %s and %s not the same length\n", argv[1], argv[3]);
+    gprint (GP_ERR, "vectors %s and %s not the same length\n", argv[1], argv[3]);
     return (FALSE);
   }