Index: trunk/Ohana/src/opihi/cmd.data/Makefile
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/Makefile	(revision 31160)
+++ trunk/Ohana/src/opihi/cmd.data/Makefile	(revision 31450)
@@ -141,4 +141,5 @@
 $(SRC)/vpop.$(ARCH).o		   \
 $(SRC)/vroll.$(ARCH).o		   \
+$(SRC)/vshift.$(ARCH).o		   \
 $(SRC)/vsmooth.$(ARCH).o	   \
 $(SRC)/vstats.$(ARCH).o		   \
Index: trunk/Ohana/src/opihi/cmd.data/gridify.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/gridify.c	(revision 31160)
+++ trunk/Ohana/src/opihi/cmd.data/gridify.c	(revision 31450)
@@ -4,5 +4,5 @@
 
   int i, Nx, Ny, Xb, Yb, Normalize, N;
-  float Xmin, Xmax, dX, Ymin, Ymax, dY;
+  float Xmin, Xmax, dX, Ymin, Ymax, dY, initValue;
   float *buf, *val;
   int *Nval;
@@ -15,4 +15,11 @@
     remove_argument (N, &argc, argv);
     Normalize = FALSE;
+  }
+
+  initValue = 0.0;
+  if ((N = get_argument (argc, argv, "-init-value"))) {
+    remove_argument (N, &argc, argv);
+    initValue = atof(argv[N]);
+    remove_argument (N, &argc, argv);
   }
 
@@ -69,7 +76,7 @@
   buf = (float *) bf[0].matrix.buffer;
   for (i = 0; i < Nx*Ny; i++) {
+    buf[i] = initValue;
     if (Normalize) {
       if (Nval[i] == 0) {
-	buf[i] = 0;
 	continue;
       }
Index: trunk/Ohana/src/opihi/cmd.data/init.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/init.c	(revision 31160)
+++ trunk/Ohana/src/opihi/cmd.data/init.c	(revision 31450)
@@ -130,4 +130,5 @@
 int vstats           PROTO((int, char **));
 int vroll            PROTO((int, char **));
+int vshift           PROTO((int, char **));
 int vpop             PROTO((int, char **));
 int vsmooth          PROTO((int, char **));
@@ -274,5 +275,6 @@
   {1, "vmaxwell",     vmaxwell,         "fit a Maxwellian to a vector"},
   {1, "vpop",         vpop,             "remove first element of a vector"},
-  {1, "vroll",        vroll,            "roll vector elements"},
+  {1, "vroll",        vroll,            "roll vector elements by 1 entry"},
+  {1, "vshift",       vshift,           "shift vector elements by arbitrary amount"},
   {1, "vsmooth",      vsmooth,          "Gaussian smooth of a vector"},
   {1, "vstats",       vstats,           "statistics on a vector"},
Index: trunk/Ohana/src/opihi/cmd.data/vshift.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/vshift.c	(revision 31450)
+++ trunk/Ohana/src/opihi/cmd.data/vshift.c	(revision 31450)
@@ -0,0 +1,73 @@
+# include "data.h"
+
+int vshift (int argc, char **argv) {
+
+  int isPos, N, Npix, Nshift, delta, ROLL;
+  Vector *ivec, *ovec;
+
+  ROLL = FALSE;
+  if ((N = get_argument (argc, argv, "-roll"))) {
+    remove_argument (N, &argc, argv);
+    ROLL = TRUE;
+  }
+
+  if (argc != 4) {
+    gprint (GP_ERR, "USAGE: vshift (input) (output) (delta) [-roll]\n");
+    gprint (GP_ERR, "  shift vector by (delta) elements\n");
+    gprint (GP_ERR, "  a positive value move element (i) to (i+delta)\n");
+    gprint (GP_ERR, "  -roll : move dropped values to the other size (no elements are lost)\n");
+    return (FALSE);
+  }
+
+  if ((ivec = SelectVector (argv[1], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((ovec = SelectVector (argv[2], ANYVECTOR, TRUE)) == NULL) return (FALSE);
+  delta = atoi(argv[3]);
+  isPos = delta > 0;
+  delta = abs(delta);
+    
+  ResetVector (ovec, ivec->type, ivec->Nelements);
+
+  Npix = ivec[0].Nelements;
+  if (delta > Npix) {
+    if (!ROLL) {
+      if (ivec[0].type == OPIHI_FLT) {
+	memset (ovec[0].elements.Flt, 0, Npix*sizeof(opihi_flt));
+      } else {
+	memset (ovec[0].elements.Flt, 0, Npix*sizeof(opihi_flt));
+      }
+      return TRUE;
+    }
+    delta = delta % Npix;
+  }
+
+  if (ivec[0].type == OPIHI_FLT) {
+    memset (ovec[0].elements.Flt, 0, Npix*sizeof(opihi_flt));
+    Nshift = Npix - delta;
+    if (isPos) {
+      memcpy (&ovec[0].elements.Flt[delta], &ivec[0].elements.Flt[0], Nshift*sizeof(opihi_flt));
+      if (ROLL) {
+	memcpy (&ovec[0].elements.Flt[0], &ivec[0].elements.Flt[Nshift], delta*sizeof(opihi_flt));
+      } 
+    } else {
+      memcpy (&ovec[0].elements.Flt[0], &ivec[0].elements.Flt[delta], Nshift*sizeof(opihi_flt));
+      if (ROLL) {
+	memcpy (&ovec[0].elements.Flt[Nshift], &ivec[0].elements.Flt[0], delta*sizeof(opihi_flt));
+      }
+    }
+  } else {
+    memset (ovec[0].elements.Int, 0, Npix*sizeof(opihi_int));
+    Nshift = Npix - delta;
+    if (isPos) {
+      memcpy (&ovec[0].elements.Int[delta], &ivec[0].elements.Int[0], Nshift*sizeof(opihi_int));
+      if (ROLL) {
+	memcpy (&ovec[0].elements.Int[0], &ivec[0].elements.Int[Nshift], delta*sizeof(opihi_int));
+      } 
+    } else {
+      memcpy (&ovec[0].elements.Int[0], &ivec[0].elements.Int[delta], Nshift*sizeof(opihi_int));
+      if (ROLL) {
+	memcpy (&ovec[0].elements.Int[Nshift], &ivec[0].elements.Int[0], delta*sizeof(opihi_int));
+      }
+    }
+  }
+  return (TRUE);
+}