Index: /trunk/Ohana/src/opihi/cmd.astro/fixwrap.c
===================================================================
--- /trunk/Ohana/src/opihi/cmd.astro/fixwrap.c	(revision 6644)
+++ /trunk/Ohana/src/opihi/cmd.astro/fixwrap.c	(revision 6644)
@@ -0,0 +1,110 @@
+# include "astro.h"
+
+int fixwrap (int argc, char **argv) {
+  
+  int i, j, Nflip, n, Ny, Nx, flip, sat, rowfix;
+  float *Vin, *outf, *outb, dV, dO;
+  Buffer *in;
+
+  if (argc != 3) {
+    fprintf (stderr, "USAGE: fixwrap <in> (rowfix)\n");
+    return (FALSE);
+  }
+
+  if ((in = SelectBuffer (argv[1], OLDBUFFER, TRUE)) == NULL) return (FALSE);
+  rowfix = atoi (argv[2]);
+
+  Nx = in[0].matrix.Naxis[0];
+  Ny = in[0].matrix.Naxis[1];
+
+  ALLOCATE (outf, float, MAX(Nx, Ny));
+  ALLOCATE (outb, float, MAX(Nx, Ny));
+
+  for (j = 0; j < Ny; j++) {
+    Vin  = (float *)(in[0].matrix.buffer)  + j*Nx;
+
+    /* measure forward flips */ 
+    sat = FALSE;
+    for (i = 0; i < Nx; i++) {
+      if ((i < 1056) || (i > 2079)) {
+	outf[i] = Vin[i];
+	continue;
+      }
+
+      dO = 2*outf[i-1] - outf[i-2] - Vin[i];
+      flip = (fabs(dO - 0x8000) < fabs(dO));
+
+      /* going onto saturation */
+      if (!sat && (Vin[i] > 32766.5) && (Vin[i+1]  > 32766.5)) sat  = TRUE;
+      if (!sat && (Vin[i] > 32766.5) && (Vin[i-Nx] > 65534.5)) sat  = TRUE;
+
+      /* exiting saturation region */
+      if ( sat && (Vin[i] < 32766.5) && (Vin[i-1] < 32766.5)) sat = FALSE;
+
+      if (sat) flip = TRUE;
+
+      outf[i] = flip ? (Vin[i] + 0x8000) : Vin[i];
+    }
+
+    /* measure backward flips */ 
+    sat = FALSE;
+    for (i = Nx - 1; i >= 0; i--) {
+      if ((i < 1056) || (i > 2077)) {
+	outb[i] = Vin[i];
+	continue;
+      }
+
+      dO = 2*outb[i+1] - outb[i+2] - Vin[i];
+      flip = (fabs(dO - 0x8000) < fabs(dO));
+
+      /* going onto saturation */
+      if (!sat && (Vin[i] > 32766.5) && (Vin[i-1] > 32766.5)) sat  = TRUE;
+
+      /* exiting saturation region */
+      if ( sat && (Vin[i] < 32766.5) && (Vin[i+1] < 32766.5)) sat = FALSE;
+
+      if (sat) flip = TRUE;
+
+      outb[i] = flip ? (Vin[i] + 0x8000) : Vin[i];
+    }
+
+    /* compare forward and backward flips: where they disagree, use column to predict */
+    for (i = 0; (j > 1) && (i < Nx); i++) {
+      if ((i < 1056) || (i > 2077)) continue;
+      if (outf[i] != outb[i]) {
+	/* use this column to predict, not the row */
+	dO = 2*Vin[i - Nx] - Vin[i-2*Nx] - Vin[i];
+	flip = (fabs(dO - 0x8000) < fabs(dO));
+	outf[i] = flip ? Vin[i] + 0x8000 : Vin[i];
+	outb[i] = outf[i];  /* save this for the row segments below */
+      }
+    }
+
+    /* compare this row and previous (now fixed) row. if large segments are flipped, fix them */
+    for (i = 0; rowfix && (j > 1) && (i < Nx); i++) {
+      if ((i < 1056) || (i > 2077)) continue;
+
+      if (fabs(outf[i] - Vin[i-Nx]) > 15000) {
+	Nflip = 0;
+	for (n = i - 8; n < i + 9; n++) {
+	  if (fabs(outb[n] - Vin[n-Nx]) > 15000) {
+	    Nflip ++;
+	  }
+	}
+	if (Nflip > 5) {
+	  if (outf[i] - Vin[i-Nx] > 15000) {
+	    outf[i] -= 0x8000;
+	  } else {
+	    outf[i] += 0x8000;
+	  }	    
+	}
+      }
+    }
+    for (i = 0; i < Nx; i++) {
+      Vin[i] = outf[i];
+    }
+  }
+
+  return (TRUE);
+}
+