Index: trunk/Ohana/src/opihi/cmd.data/Makefile
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/Makefile	(revision 25584)
+++ trunk/Ohana/src/opihi/cmd.data/Makefile	(revision 25757)
@@ -97,4 +97,5 @@
 $(SRC)/rebin.$(ARCH).o		\
 $(SRC)/resize.$(ARCH).o	\
+$(SRC)/relocate.$(ARCH).o	\
 $(SRC)/roll.$(ARCH).o		\
 $(SRC)/rotate.$(ARCH).o	\
@@ -110,5 +111,5 @@
 $(SRC)/style.$(ARCH).o		   \
 $(SRC)/subraster.$(ARCH).o	   \
-$(SRC)/subset.$(ARCH).o	   \
+$(SRC)/subset.$(ARCH).o	           \
 $(SRC)/svd.$(ARCH).o		   \
 $(SRC)/swapbytes.$(ARCH).o	   \
@@ -118,11 +119,13 @@
 $(SRC)/tvcolors.$(ARCH).o	   \
 $(SRC)/tvcontour.$(ARCH).o	   \
-$(SRC)/tvgrid.$(ARCH).o	   \
+$(SRC)/tvgrid.$(ARCH).o	           \
 $(SRC)/uniq.$(ARCH).o		   \
-$(SRC)/unsign.$(ARCH).o	   \
+$(SRC)/unsign.$(ARCH).o	           \
 $(SRC)/vbin.$(ARCH).o		   \
+$(SRC)/vgroup.$(ARCH).o		   \
 $(SRC)/vclip.$(ARCH).o		   \
-$(SRC)/vgauss.$(ARCH).o           \
-$(SRC)/vmaxwell.$(ARCH).o           \
+$(SRC)/vgauss.$(ARCH).o            \
+$(SRC)/vellipse.$(ARCH).o          \
+$(SRC)/vmaxwell.$(ARCH).o          \
 $(SRC)/vgrid.$(ARCH).o		   \
 $(SRC)/vload.$(ARCH).o		   \
@@ -130,5 +133,5 @@
 $(SRC)/vpop.$(ARCH).o		   \
 $(SRC)/vroll.$(ARCH).o		   \
-$(SRC)/vsmooth.$(ARCH).o	\
+$(SRC)/vsmooth.$(ARCH).o	   \
 $(SRC)/vstats.$(ARCH).o		   \
 $(SRC)/wd.$(ARCH).o		   \
Index: trunk/Ohana/src/opihi/cmd.data/init.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/init.c	(revision 25584)
+++ trunk/Ohana/src/opihi/cmd.data/init.c	(revision 25757)
@@ -85,4 +85,5 @@
 int rebin            PROTO((int, char **));
 int resize           PROTO((int, char **));
+int relocate         PROTO((int, char **));
 int roll             PROTO((int, char **));
 int rotate           PROTO((int, char **));
@@ -110,8 +111,10 @@
 int unsign           PROTO((int, char **));
 int vbin             PROTO((int, char **));
+int vgroup           PROTO((int, char **));
 int vclip            PROTO((int, char **));
 int vect_select      PROTO((int, char **));
 int vgrid            PROTO((int, char **));
 int vgauss           PROTO((int, char **));
+int vellipse         PROTO((int, char **));
 int vmaxwell         PROTO((int, char **));
 int vload            PROTO((int, char **));
@@ -218,4 +221,5 @@
   {1, "rebin",        rebin,            "rebin image data by factor of N"},
   {1, "resize",       resize,           "set graphics/image window size"},
+  {1, "relocate",     relocate,         "set graphics/image window position"},
   {1, "roll",         roll,             "roll image to new start point"},
   {1, "rotate",       rotate,           "rotate image"},
@@ -243,8 +247,10 @@
   {1, "uniq",         uniq,             "create a uniq vector subset from a vector"},
   {1, "unsign",       unsign,           "toggle the UNSIGN status"},
-  {1, "vbin",         vbin,             "rebin vector data by a fector of N"},
+  {1, "vbin",         vbin,             "rebin vector data by a factor of N"},
+  {1, "vgroup",       vgroup,           "group y vector into bins defined by x vector values"},
   {1, "vclip",        vclip,            "clip values in a vector to be within a range"},
   {1, "vectors",      list_vectors,     "list vectors"},
   {1, "vgauss",       vgauss,           "fit a Gaussian to a vector"},
+  {1, "vellipse",     vellipse,         "fit a Ellipse to a vector pair"},
   {1, "vgrid",        vgrid,            "generate an image from a triplet of vectors"},
   {1, "vhistogram",   histogram,        "generate histogram from vector"},
Index: trunk/Ohana/src/opihi/cmd.data/relocate.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/relocate.c	(revision 25757)
+++ trunk/Ohana/src/opihi/cmd.data/relocate.c	(revision 25757)
@@ -0,0 +1,33 @@
+# include "data.h"
+
+int relocate (int argc, char **argv) {
+
+  char *end;
+  int x, y;
+  int N, kapa;
+  char *name;
+  
+  /* display source */
+  name = NULL;
+  if ((N = get_argument (argc, argv, "-n"))) {
+    remove_argument (N, &argc, argv);
+    name = strcreate (argv[N]);
+    remove_argument (N, &argc, argv);
+  }
+  if (!GetImage (NULL, &kapa, name)) return (FALSE);
+  FREE (name);
+
+  if (argc != 3) {
+    gprint (GP_ERR, "USAGE: relocate x y [-n]\n");
+    return (FALSE);
+  }
+
+  /* x & y are pixels for the screen -- this command has no meaning for non-X */
+
+  x = atoi (argv[1]);
+  y = atoi (argv[2]);
+
+  KiiRelocate (kapa, x, y);
+  return (TRUE);
+}
+
Index: trunk/Ohana/src/opihi/cmd.data/subset.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/subset.c	(revision 25584)
+++ trunk/Ohana/src/opihi/cmd.data/subset.c	(revision 25757)
@@ -6,5 +6,5 @@
   
   char *out;
-  int  i, Npts, size;
+  int  i, Npts, size, valid;
   Vector *ivec, *ovec, *tvec;
 
@@ -12,6 +12,10 @@
   ivec = ovec = tvec = NULL;
 
-  if ((argc < 6) || strcmp(argv[2], "=") || strcmp (argv[4], "if")) {
-    gprint (GP_ERR, "SYNTAX: subset vec = vec if (logic expression)\n");
+  valid = TRUE;
+  valid &= (argc >= 6);
+  valid &= !strcmp(argv[2], "=");
+  valid &= !strcmp(argv[4], "if") || !strcmp (argv[4], "where");
+  if (!valid) {
+    gprint (GP_ERR, "SYNTAX: subset vec = vec [if/where] (logic expression)\n");
     return (FALSE);
   }
@@ -76,5 +80,5 @@
   return (TRUE);
 
- error:
+error:
   DeleteVector (tvec);
   DeleteVector (ovec);
Index: trunk/Ohana/src/opihi/cmd.data/tvcolors.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/tvcolors.c	(revision 25584)
+++ trunk/Ohana/src/opihi/cmd.data/tvcolors.c	(revision 25757)
@@ -19,4 +19,5 @@
   if (argc != 2) {
     gprint (GP_ERR, "USAGE: tvcolors (colormap)\n");
+    gprint (GP_ERR, " colormap options : greyscale, -greyscale, rainbow, heat, fullcolor, ruffcolor (also grayscale, -grayscale)\n");
     return (FALSE);
   }
Index: trunk/Ohana/src/opihi/cmd.data/vellipse.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/vellipse.c	(revision 25757)
+++ trunk/Ohana/src/opihi/cmd.data/vellipse.c	(revision 25757)
@@ -0,0 +1,272 @@
+# include "data.h"
+
+/* local private functions */
+opihi_flt fellipseOD (opihi_flt theta, opihi_flt *par, int Npar, opihi_flt *dpar);
+
+// enum {PAR_X0, PAR_Y0, PAR_RX, PAR_RY, PAR_T0, PAR_P0};
+enum {PAR_RMIN, PAR_EPSILON, PAR_PHI};
+
+# define GET_VAR(V,A) { \
+  char *c; \
+  c = get_variable (A); \
+  if (c == NULL) { \
+    gprint (GP_ERR, "missing fit parameter A\n"); \
+    return (FALSE); \
+  } \
+  V = atof (c); \
+  free (c); }
+
+int vellipse (int argc, char **argv) {
+
+  int i, N, Npts, Npar, Quiet;
+  opihi_flt par[6], *pos, *dpos, *theta, **covar;
+  opihi_flt chisq, ochisq, dchisq;
+  // opihi_flt Rmaj;
+  opihi_flt Xmin, Xmax, Ymin, Ymax;
+  Vector *xvec, *yvec, *Xvec, *Yvec, *tvec;
+
+  Quiet = FALSE;
+  if ((N = get_argument (argc, argv, "-q"))) {
+    Quiet = TRUE;
+    remove_argument (N, &argc, argv);
+  }
+  if ((N = get_argument (argc, argv, "-quiet"))) {
+    Quiet = TRUE;
+    remove_argument (N, &argc, argv);
+  }
+
+  if (argc != 6) {
+    gprint (GP_ERR, "USAGE: vellipse <xobs> <yobs> <xfit> <yfit> (theta)\n");
+    // gprint (GP_ERR, " uses guesses: E_X0, E_Y0, E_RMAJ, E_RMIN, E_THETA\n");
+    gprint (GP_ERR, " uses guesses: E_RMAJ, E_RMIN, E_PHI\n");
+    return (FALSE);
+  }
+  
+  if ((xvec = SelectVector (argv[1], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((yvec = SelectVector (argv[2], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((Xvec = SelectVector (argv[3], ANYVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((Yvec = SelectVector (argv[4], ANYVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((tvec = SelectVector (argv[5], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+
+  REQUIRE_VECTOR_FLT (xvec, FALSE); 
+  REQUIRE_VECTOR_FLT (yvec, FALSE); 
+
+  // GET_VAR (par[PAR_X0], "E_X0");
+  // GET_VAR (par[PAR_Y0], "E_Y0");
+  // GET_VAR (par[PAR_RX], "E_RMAJ");
+  // GET_VAR (par[PAR_RY], "E_RMIN");
+  // GET_VAR (par[PAR_T0], "E_THETA");
+  // GET_VAR (par[PAR_P0], "E_PHI");
+  // Npar = 6;
+
+  // we need to generate a vector of alternating x,y values and the independent variable theta:
+  Xmax = Ymax = Xmin = Ymin = 0.0;
+  ALLOCATE (pos,   opihi_flt, 2*xvec[0].Nelements); 
+  ALLOCATE (dpos,  opihi_flt, 2*xvec[0].Nelements); 
+  ALLOCATE (theta, opihi_flt, 2*xvec[0].Nelements); 
+  for (i = 0; i < xvec[0].Nelements; i++) {
+    pos[2*i+0]   = xvec[0].elements.Flt[i];
+    pos[2*i+1]   = yvec[0].elements.Flt[i];
+    Xmin = MIN (Xmin, xvec[0].elements.Flt[i]);
+    Xmax = MAX (Xmax, xvec[0].elements.Flt[i]);
+    Ymin = MIN (Ymin, yvec[0].elements.Flt[i]);
+    Ymax = MAX (Ymax, yvec[0].elements.Flt[i]);
+    dpos[2*i+0]  = 1.0;
+    dpos[2*i+1]  = 1.0;
+    theta[2*i+0] = atan2(yvec[0].elements.Flt[i], xvec[0].elements.Flt[i]);
+    theta[2*i+1] = theta[2*i+0];
+    // fprintf (stderr, "x,y: %f, %f -> %f, %f\n", yvec[0].elements.Flt[i], xvec[0].elements.Flt[i], yvec[0].elements.Flt[i] - par[PAR_Y0], xvec[0].elements.Flt[i] - par[PAR_X0]);
+    // fprintf (stderr, "x,y: %f, %f -> %f, %f\n", yvec[0].elements.Flt[i], xvec[0].elements.Flt[i], yvec[0].elements.Flt[i] - par[PAR_Y0], xvec[0].elements.Flt[i] - par[PAR_X0]);
+    // fprintf (stderr, "theta: %f - %f : %f\n", DEG_RAD*theta[2*i+0], tvec[0].elements.Flt[i], DEG_RAD*theta[2*i+0] - tvec[0].elements.Flt[i]);
+  }
+  Npts = 2*xvec[0].Nelements;
+
+  // basic guess from range, PHI in degrees, converted to radians
+  // GET_VAR (Rmaj,          "E_RMAJ");
+  // GET_VAR (par[PAR_RMIN], "E_RMIN");
+  // GET_VAR (par[PAR_PHI],  "E_PHI");
+  par[PAR_PHI] = 0.0;
+  par[PAR_EPSILON] = 0.5;
+  par[PAR_RMIN] = 0.25*((Xmax - Xmin) + (Ymax - Ymin));
+  Npar = 3;
+
+  ochisq = mrqinit (theta, pos, dpos, Npts, par, Npar, fellipseOD, !Quiet);
+  dchisq = ochisq + 2*Npts;
+  chisq  = ochisq + dchisq;
+
+  for (i = 0; (i < 20) && (chisq > 1e-3) && ((dchisq > 0.001*(Npts - Npar)) || (dchisq <= 0.0)); i++) {
+    chisq = mrqmin (theta, pos, dpos, Npts, par, Npar, fellipseOD, !Quiet);
+    dchisq = ochisq - chisq;
+    ochisq = chisq;
+    if (!Quiet) gprint (GP_ERR, "dchisq: %f, Ndof: %d\n", dchisq, Npts - Npar);
+  }  
+  if (!Quiet) gprint (GP_ERR, "%d iterations\n", i); 
+
+  ResetVector (Xvec, OPIHI_FLT, xvec[0].Nelements);
+  ResetVector (Yvec, OPIHI_FLT, xvec[0].Nelements);
+  for (i = 0; i < xvec[0].Nelements; i++) {
+    Xvec[0].elements.Flt[i] = fellipseOD (theta[2*i+0], par, Npar, dpos);
+    Yvec[0].elements.Flt[i] = fellipseOD (theta[2*i+1], par, Npar, dpos);
+  }
+  Xvec[0].Nelements = xvec[0].Nelements;
+  Yvec[0].Nelements = xvec[0].Nelements;
+
+  covar = mrqcovar (Npar);
+  //set_variable ("E_X0",   par[PAR_X0]);
+  //set_variable ("E_Y0",   par[PAR_Y0]);
+  //set_variable ("E_RMAJ", par[PAR_RX]);
+  //set_variable ("E_RMIN", par[PAR_RY]);
+  //set_variable ("E_T0",   par[PAR_T0]);
+  //set_variable ("E_P0",   par[PAR_P0]);
+
+  set_variable ("E_RMAJ", par[PAR_RMIN] / par[PAR_EPSILON]);
+  set_variable ("E_RMIN", par[PAR_RMIN]);
+  set_variable ("E_PHI",  DEG_RAD*par[PAR_PHI]);
+
+  // set_variable ("dE_X0",   sqrt(covar[PAR_X0][PAR_X0]));
+  // set_variable ("dE_Y0",   sqrt(covar[PAR_Y0][PAR_Y0]));
+  // set_variable ("dE_RMAJ", sqrt(covar[PAR_RX][PAR_RX]));
+  // set_variable ("dE_RMIN", sqrt(covar[PAR_RY][PAR_RY]));
+  // set_variable ("dE_T0",   sqrt(covar[PAR_T0][PAR_T0]));
+  // set_variable ("dE_P0",   sqrt(covar[PAR_P0][PAR_P0]));
+
+  set_variable ("dE_RMAJ", sqrt(covar[PAR_EPSILON][PAR_EPSILON]*covar[PAR_RMIN][PAR_RMIN]));
+  set_variable ("dE_RMIN", sqrt(covar[PAR_RMIN][PAR_RMIN]));
+  set_variable ("dE_PHI",  DEG_RAD*sqrt(covar[PAR_PHI][PAR_PHI]));
+
+  // if (!Quiet) gprint (GP_ERR, "Xo : %f +/- %f\n", par[PAR_X0], sqrt(covar[PAR_X0][PAR_X0]));
+  // if (!Quiet) gprint (GP_ERR, "Yo : %f +/- %f\n", par[PAR_Y0], sqrt(covar[PAR_Y0][PAR_Y0]));
+  // if (!Quiet) gprint (GP_ERR, "RX : %f +/- %f\n", par[PAR_RX], sqrt(covar[PAR_RX][PAR_RX]));
+  // if (!Quiet) gprint (GP_ERR, "RY : %f +/- %f\n", par[PAR_RY], sqrt(covar[PAR_RY][PAR_RY]));
+  // if (!Quiet) gprint (GP_ERR, "To : %f +/- %f\n", par[PAR_T0], sqrt(covar[PAR_T0][PAR_T0]));
+  // if (!Quiet) gprint (GP_ERR, "Po : %f +/- %f\n", par[PAR_P0], sqrt(covar[PAR_P0][PAR_P0]));
+
+  if (!Quiet) gprint (GP_ERR, "RMAJ : %f +/- %f\n", par[PAR_RMIN] / par[PAR_EPSILON], 0.0);
+  if (!Quiet) gprint (GP_ERR, "RMIN : %f +/- %f\n", par[PAR_RMIN], sqrt(covar[PAR_RMIN][PAR_RMIN]));
+  if (!Quiet) gprint (GP_ERR, "PHI  : %f +/- %f\n", DEG_RAD*par[PAR_PHI],  sqrt(covar[PAR_PHI][PAR_PHI]));
+
+  free (pos);
+  free (dpos);
+  free (theta);
+
+  mrqfree (Npar);
+  return (TRUE);
+}
+
+# if (0)
+/**
+ * the full chisq is built of two associated sums over coordinates:
+ * chisq = sum ((X_obs - X_fit(t))^2 + (Y_obs - Y_fit(t))^2)
+ * 
+ * the independent variable is Theta:
+ * X_fit = X0 + RX*cos(theta)*cos(phi) - RY*sin(theta)*sin(phi)
+ * Y_fit = Y0 + RX*cos(theta)*sin(phi) + RY*sin(theta)*cos(phi)
+ *
+ * alternating calls to fellipseOD refer alternatively to X or Y
+ *
+ * parameters: Xo, Yo (center), RX, RY (axes), To (angle), Po (phase)
+ */
+
+opihi_flt fellipseOD (opihi_flt theta, opihi_flt *par, int Npar, opihi_flt *dpar) {
+  
+  static int pass = 0;
+
+  opihi_flt csphi = cos(par[PAR_P0]);
+  opihi_flt snphi = sin(par[PAR_P0]);
+
+  opihi_flt dtheta = theta - par[PAR_T0];
+  opihi_flt cstht = cos(dtheta);
+  opihi_flt sntht = sin(dtheta);
+
+  // value is X
+  if (pass == 0) {
+    pass = 1;
+
+    opihi_flt value = par[PAR_X0] + par[PAR_RX]*cstht*csphi - par[PAR_RY]*sntht*snphi;
+
+    dpar[PAR_X0] = 1.0;
+    dpar[PAR_Y0] = 0.0;
+    dpar[PAR_RX] = +cstht*csphi;
+    dpar[PAR_RY] = -sntht*snphi;
+    dpar[PAR_P0] = -par[PAR_RX]*cstht*snphi - par[PAR_RY]*sntht*csphi;
+    dpar[PAR_T0] = -par[PAR_RX]*sntht*csphi - par[PAR_RY]*cstht*snphi;
+
+    return (value);
+  }  
+
+  // value is Y
+  if (pass == 1) {
+    pass = 0;
+
+    opihi_flt value = par[PAR_Y0] + par[PAR_RX]*cstht*snphi + par[PAR_RY]*sntht*csphi;
+
+    dpar[PAR_X0]  = 0.0;
+    dpar[PAR_Y0]  = 1.0;
+    dpar[PAR_RX]  = +cstht*snphi;
+    dpar[PAR_RY]  = +sntht*csphi;
+    dpar[PAR_P0]  = +par[PAR_RX]*cstht*csphi - par[PAR_RY]*sntht*snphi;
+    dpar[PAR_T0]  = -par[PAR_RX]*sntht*snphi + par[PAR_RY]*cstht*csphi;
+    return (value);
+  }  
+  abort();
+}
+
+# endif
+
+/**
+ * the full chisq is built of two associated sums over coordinates:
+ * chisq = sum ((X_obs - X_fit(t))^2 + (Y_obs - Y_fit(t))^2)
+ * 
+ * the independent variable is theta (angle from 0,0 to point):
+ * X_fit = RMIN*R*cos(theta)
+ * Y_fit = RMIN*R*sin(theta)
+ * R = 1 / sqrt(sin^2(theta-phi) + epsilon^2 * cos^2(theta-phi))
+ *
+ * alternating calls to fellipseOD refer alternatively to X or Y
+ *
+ * RMIN, EPSILON, PHI
+ */
+
+opihi_flt fellipseOD (opihi_flt alpha, opihi_flt *par, int Npar, opihi_flt *dpar) {
+  
+  static int pass = 0;
+
+  opihi_flt cs_alpha = cos(alpha);
+  opihi_flt sn_alpha = sin(alpha);
+
+  opihi_flt cs_phi = cos(alpha - par[PAR_PHI]);
+  opihi_flt sn_phi = sin(alpha - par[PAR_PHI]);
+
+  opihi_flt r     = 1.0 / sqrt(SQ(sn_phi) + SQ(par[PAR_EPSILON]*cs_phi));
+  opihi_flt r3    = pow(r, 3.0);
+  opihi_flt drdE  = -0.5 * r3 * SQ(cs_phi) * 2.0 * par[PAR_EPSILON];
+  opihi_flt drdP  = -0.5 * r3 * (SQ(par[PAR_EPSILON]) - 1) * 2.0 * cs_phi * sn_phi;
+
+  // value is X
+  if (pass == 0) {
+    pass = 1;
+
+    opihi_flt value = par[PAR_RMIN]*cs_alpha*r;
+
+    dpar[PAR_RMIN]    = r*cs_alpha;
+    dpar[PAR_EPSILON] = par[PAR_RMIN]*cs_alpha*drdE;
+    dpar[PAR_PHI]     = 4.0*par[PAR_RMIN]*cs_alpha*drdP;
+
+    return (value);
+  }  
+
+  // value is Y
+  if (pass == 1) {
+    pass = 0;
+
+    opihi_flt value = par[PAR_RMIN]*sn_alpha*r;
+
+    dpar[PAR_RMIN]    = r*sn_alpha;
+    dpar[PAR_EPSILON] = par[PAR_RMIN]*sn_alpha*drdE;
+    dpar[PAR_PHI]     = 4.0*par[PAR_RMIN]*sn_alpha*drdP;
+
+    return (value);
+  }  
+  abort();
+}
+
Index: trunk/Ohana/src/opihi/cmd.data/vgroup.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/vgroup.c	(revision 25757)
+++ trunk/Ohana/src/opihi/cmd.data/vgroup.c	(revision 25757)
@@ -0,0 +1,71 @@
+# include "data.h"
+
+int vgroup (int argc, char **argv) {
+  
+  int i, j, N;
+  Vector *xin, *yin, *xout, *yout;
+  opihi_flt xmin, xmax, sum;
+  double *values;
+
+  // Normalize = FALSE;
+  // if ((N = get_argument (argc, argv, "-norm"))) {
+  //   remove_argument (N, &argc, argv);
+  //   Normalize = TRUE;
+  // }
+  // 
+  // Ignore = FALSE;
+  // IgnoreValue = 0.0;
+  // if ((N = get_argument (argc, argv, "-ignore"))) {
+  //   Ignore = TRUE;
+  //   remove_argument (N, &argc, argv);
+  //   IgnoreValue = atof (argv[N]);
+  //   remove_argument (N, &argc, argv);
+  // }
+
+  if (argc != 5) {
+    gprint (GP_ERR, "USAGE: vbin <xin> <yin> <xout> <yout>\n");
+    gprint (GP_ERR, " group x,y values in bins defined by <xout>\n");
+    return (FALSE);
+  }
+
+  if ((xin  = SelectVector (argv[1], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((yin  = SelectVector (argv[2], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((xout = SelectVector (argv[3], OLDVECTOR, TRUE)) == NULL) return (FALSE);
+  if ((yout = SelectVector (argv[4], ANYVECTOR, TRUE)) == NULL) return (FALSE);
+
+  // re-binning creates a float vector
+  ResetVector (yout, OPIHI_FLT, xout[0].Nelements);
+
+  // storage vector
+  ALLOCATE (values, double, xin[0].Nelements);
+
+  for (i = 0; i < xout[0].Nelements - 1; i++) {
+    xmin = xout[0].elements.Flt[i];
+    xmax = xout[0].elements.Flt[i+1];
+
+    N = 0;
+    for (j = 0; j < xin[0].Nelements; j++) {
+      if (xin[0].elements.Flt[j] < xmin) continue;
+      if (xin[0].elements.Flt[j] > xmax) continue;
+      values[N] = yin[0].elements.Flt[j];
+      N++;
+    }
+    
+    dsort (values, N);
+    if (N > 1) {
+      sum = (N % 2) ? values[(int)(0.5*N)] : 0.5*(values[N/2] + values[N/2 + 1]);
+    } else {
+      sum = values[0];
+    }
+
+    // measure the stat for this bin
+    // sum = 0.0;
+    // for (j = 0; j < N; j++) {
+    //   sum += values[j];
+    // }
+    // sum /= N;
+    yout[0].elements.Flt[i] = sum;
+  }
+  free (values);
+  return (TRUE);
+}