Index: trunk/Ohana/src/opihi/cmd.data/zplot.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/zplot.c	(revision 34613)
+++ trunk/Ohana/src/opihi/cmd.data/zplot.c	(revision 38062)
@@ -4,11 +4,34 @@
   
   char *outname = NULL;
-  int i, kapa, valid, size;
+  int i, N, kapa, valid, size;
   opihi_flt *out;
   double min, range;
   Graphdata graphmode;
-  Vector *xvec, *yvec, *zvec, Zvec;
+  Vector *xvec, *yvec, *zvec, *dxmvec, *dxpvec, *dymvec, *dypvec, Zvec;
 
   if (!style_args (&graphmode, &argc, argv, &kapa)) return (FALSE);
+
+  /* decide on error bars */
+  dxmvec = dxpvec = dymvec = dypvec = NULL;
+  if ((N = get_argument (argc, argv, "-dx"))) {
+    remove_argument (N, &argc, argv);
+    if ((dxmvec = SelectVector (argv[N], OLDVECTOR, TRUE)) == NULL) return (FALSE);    
+    remove_argument (N, &argc, argv);
+  }
+  if ((N = get_argument (argc, argv, "+dx"))) {
+    remove_argument (N, &argc, argv);
+    if ((dxpvec = SelectVector (argv[N], OLDVECTOR, TRUE)) == NULL) return (FALSE);    
+    remove_argument (N, &argc, argv);
+  }
+  if ((N = get_argument (argc, argv, "-dy"))) {
+    remove_argument (N, &argc, argv);
+    if ((dymvec = SelectVector (argv[N], OLDVECTOR, TRUE)) == NULL) return (FALSE);    
+    remove_argument (N, &argc, argv);
+  }
+  if ((N = get_argument (argc, argv, "+dy"))) {
+    remove_argument (N, &argc, argv);
+    if ((dypvec = SelectVector (argv[N], OLDVECTOR, TRUE)) == NULL) return (FALSE);    
+    remove_argument (N, &argc, argv);
+  }
 
   valid  = (argc == 6);
@@ -40,4 +63,13 @@
   }
 
+  /* set errorbar mode (these are NOT sticky) */
+  graphmode.etype = 0;
+  if ((dymvec != NULL) && (dypvec == NULL)) dypvec = dymvec;
+  if ((dypvec != NULL) && (dymvec == NULL)) dymvec = dypvec;
+  if ((dypvec != NULL) || (dymvec != NULL)) graphmode.etype |= 0x01;
+  if ((dxmvec != NULL) && (dxpvec == NULL)) dxpvec = dxmvec;
+  if ((dxpvec != NULL) && (dxmvec == NULL)) dxmvec = dxpvec;
+  if ((dxpvec != NULL) || (dxmvec != NULL)) graphmode.etype |= 0x02;
+  
   /* find vectors */
   if ((xvec = SelectVector (argv[1], OLDVECTOR, TRUE)) == NULL) return (FALSE);
@@ -56,7 +88,13 @@
     return (FALSE);
   }
+  if (dypvec && (dypvec->Nelements != xvec->Nelements)) goto mismatch;
+  if (dymvec && (dymvec->Nelements != xvec->Nelements)) goto mismatch;
+  if (dxpvec && (dxpvec->Nelements != xvec->Nelements)) goto mismatch;
+  if (dxmvec && (dxmvec->Nelements != xvec->Nelements)) goto mismatch;
+
   SetVector (&Zvec, OPIHI_FLT, zvec[0].Nelements);
   out = Zvec.elements.Flt;
  
+  // note actual size is 3.3x plot -sz sizes. (DrawObjects.c:399)
   if (zvec[0].type == OPIHI_FLT) {
     opihi_flt *in = zvec[0].elements.Flt;
@@ -81,13 +119,31 @@
   graphmode.style = 2; /* plot points */
   graphmode.size = -1; /* point size determined by Zvec */
-  graphmode.etype = 0; /* no errorbars */
   PlotVectorTriplet (kapa, xvec, yvec, &Zvec, mask, &graphmode);
+  if (graphmode.etype & 0x01) {
+    PlotVectorSingle (kapa, dymvec, mask, "dym");
+    PlotVectorSingle (kapa, dypvec, mask, "dyp");
+  }
+  if (graphmode.etype & 0x02) {
+    PlotVectorSingle (kapa, dxmvec, mask, "dxm");
+    PlotVectorSingle (kapa, dxpvec, mask, "dxp");
+  }
 
   free (Zvec.elements.Ptr);
   if (mask) free (mask);
-  DeleteNamedVector (outname);
+
+  if (outname) {
+    DeleteNamedVector (outname);
+    free (outname);
+  }
 
   return (TRUE);
 
+mismatch:
+  gprint (GP_ERR, "error and data vector lengths are mismatched\n");
+  if (outname) {
+    DeleteNamedVector (outname);
+    free (outname);
+  }
+  return (FALSE);
 }