Index: trunk/Ohana/src/opihi/cmd.data/roll.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/roll.c	(revision 41164)
+++ trunk/Ohana/src/opihi/cmd.data/roll.c	(revision 41340)
@@ -3,9 +3,7 @@
 int roll (int argc, char **argv) {
   
+  int Nbytes, Nextra;
+  int dX, dx, dy, nx, ny;
   Buffer *buf;
-
-  // this function is probably not needed
-  gprint (GP_ERR, "ERROR: use 'shift' instead of 'roll'\n");
-  return (FALSE);
 
   if (argc != 4) {
@@ -16,71 +14,32 @@
   if ((buf = SelectBuffer (argv[1], OLDBUFFER, TRUE)) == NULL) return (FALSE);
 
-  int dx = atoi (argv[2]);
-  int dy = atoi (argv[3]);
-
-  /* if (dx,dy < 0), we are moving the start position backwards,
-     if (dx,dy > 0), we are moving the start position forward */
-  
-  int Nx = buf[0].matrix.Naxis[0];
-  int Ny = buf[0].matrix.Naxis[1];
-
-  if (dy == 0) {
-    // moves in just dx can be done row-by-row
-
-    int dX = abs(dx);
-    int Nbytes = (Nx * Ny - dX) * sizeof (float);
-    int Nextra = dX * sizeof (float);
-
-    if (dx < 0) {
-      memmove (buf[0].matrix.buffer, &buf[0].matrix.buffer[dX*sizeof(float)], Nbytes);
-      memset (&buf[0].matrix.buffer[Nbytes], 0, Nextra);
-    } else {
-      memmove (&buf[0].matrix.buffer[dX*sizeof(float)], buf[0].matrix.buffer, Nbytes);
-      memset (buf[0].matrix.buffer, 0, Nextra);
-    }
-
-    return TRUE;
+  dx = atof (argv[2]);
+  dy = atof (argv[3]);
+  if (dy != 0) {
+    gprint (GP_ERR, "only x rolls implemented for now\n");
   }
 
-  if (dx == 0) {
-    // moves in just dy can be done row-by-row
+  /* if (dx < 0), we are moving the start position back by dx pixels,
+     if (dx > 0), we are moving the start position forward by dx pixels */
+  
+  nx = buf[0].matrix.Naxis[0];
+  ny = buf[0].matrix.Naxis[1];
 
-    ALLOCATE_PTR (output, float, Nx*Ny);
+  dX = abs(dx);
+  Nbytes = nx * ny * sizeof (float);
+  Nextra = (nx * ny + dX) * sizeof (float);
 
-    float *input = (float *) buf[0].matrix.buffer;
+  REALLOCATE (buf[0].matrix.buffer, char, Nextra);
 
-    for (int iy = 0; iy < Ny; iy++) {
-      if (iy + dy < 0) continue;
-      if (iy + dy >= Ny) continue;
-      memcpy (&output[iy*Nx], &input[(iy + dy)*Nx], Nx);
-    }
-    if (dy > 0) {
-      memset (output, 0, dy*Nx*sizeof(float));
-    } else {
-      int Nbytes = Nx * (Ny - abs(dy)) * sizeof (float);
-      int Nextra = abs(dy) * Nx * sizeof (float);
-      memset (&output[Nbytes], 0, Nextra);
-    }
-    free (buf[0].matrix.buffer);
-    buf[0].matrix.buffer = (char *) output;
-    return TRUE;
+  if (dx < 0) {
+    memmove (buf[0].matrix.buffer, &buf[0].matrix.buffer[dX*sizeof(float)], Nbytes);
+  } else {
+    memmove (&buf[0].matrix.buffer[dX*sizeof(float)], buf[0].matrix.buffer, Nbytes);
   }
 
-  ALLOCATE_PTR (output, float, Nx*Ny);
-  float *input = (float *) buf[0].matrix.buffer;
+  REALLOCATE (buf[0].matrix.buffer, char, Nbytes);
 
-  for (int iy = 0; iy < Ny; iy++) {
-    if (iy + dy < 0) continue;
-    if (iy + dy >= Ny) continue;
-    for (int ix = 0; ix < Nx; ix++) {
-      if (ix + dx < 0) continue;
-      if (ix + dx >= Nx) continue;
-      output[ix + iy*Nx] = input[(ix + dx) + (iy + dy)*Nx];
-    }
-  }
-  free (buf[0].matrix.buffer);
-  buf[0].matrix.buffer = (char *) output;
-  return TRUE;
+  return (TRUE);
+
 }
 
-