Index: trunk/psModules/src/astrom/pmAstrometryVisual.c
===================================================================
--- trunk/psModules/src/astrom/pmAstrometryVisual.c	(revision 25729)
+++ trunk/psModules/src/astrom/pmAstrometryVisual.c	(revision 26260)
@@ -450,5 +450,5 @@
 
     graphdata.color = KapaColorByName ("red");
-    graphdata.style = 1;
+    graphdata.style = 0;
 
     //overplot clumpy regions excluded from analysis
@@ -905,6 +905,8 @@
     KapaPlotVector (kapa, gridNP->numCols, horizontalIndices, "x");
     KapaPlotVector (kapa, gridNP->numCols, horizHistSlice, "y");
+
     float xslice[2] = {offsetX - Scale / 2., offsetX - Scale / 2.};
     float yslice[2] = {-5, 100};
+    graphdata.style = 0;
     graphdata.color = KapaColorByName("red");
     KapaPrepPlot(kapa, 2, &graphdata);
@@ -927,6 +929,8 @@
     KapaPlotVector (kapa, gridNP->numRows, vertHistSlice, "x");
     KapaPlotVector (kapa, gridNP->numRows, verticalIndices, "y");
+
     yslice[0] = yslice[1] = offsetY - Scale / 2.;
     xslice[0] = -5; xslice[1] = 100;
+    graphdata.style = 0;
     graphdata.color = KapaColorByName("red");
     KapaPrepPlot(kapa, 2, &graphdata);
@@ -940,4 +944,105 @@
 } // end of pmAstromVisualPlotGridMatch
 
+
+bool pmAstromVisualPlotGridMatchOverlay (const psArray *raw,
+					 const psArray *ref)
+{
+    //make sure we want to plot this
+    if (!pmVisualIsVisual() || !plotGridMatch) return true;
+    if (!pmVisualInitWindow(&kapa2, "psastro:plots")){
+        return false;
+    }
+
+    Graphdata graphdata;
+    psVector *xPlot = psVectorAlloc (PS_MAX(raw->n, ref->n), PS_TYPE_F32); // x data points
+    psVector *yPlot = psVectorAlloc (PS_MAX(raw->n, ref->n), PS_TYPE_F32); // y data points
+    psVector *zPlot = psVectorAlloc (PS_MAX(raw->n, ref->n), PS_TYPE_F32); // y data points
+
+    // set up plot information
+    KapaClearPlots(kapa2);
+    KapaInitGraph(&graphdata);
+
+    KapaSetFont(kapa2, "helvetica", 14);
+    KapaBox(kapa2, &graphdata);
+    KapaSendLabel (kapa2, "X (FP)", KAPA_LABEL_XM);
+    KapaSendLabel (kapa2, "Y (FP)", KAPA_LABEL_YM);
+    KapaSendLabel (kapa2, "pmAstromGridAngle residuals. Box: Correlation Peak.", KAPA_LABEL_XP);
+
+    // plot the REF data.  (also calculate the plot ranges, accumulate the plot vectors)
+    graphdata.xmin = +INT_MAX;
+    graphdata.xmax = -INT_MAX;
+    graphdata.ymin = +INT_MAX;
+    graphdata.ymax = -INT_MAX;
+    for (int i = 0; i < ref->n; i++) {
+        pmAstromObj *obj = ref->data[i];
+	graphdata.xmin = PS_MIN(graphdata.xmin, obj->FP->x);
+	graphdata.xmax = PS_MAX(graphdata.xmax, obj->FP->x);
+	graphdata.ymin = PS_MIN(graphdata.ymin, obj->FP->y);
+	graphdata.ymax = PS_MAX(graphdata.ymax, obj->FP->y);
+	xPlot->data.F32[i] = obj->FP->x;
+	yPlot->data.F32[i] = obj->FP->y;
+	zPlot->data.F32[i] = obj->Mag;
+    }
+    xPlot->n = yPlot->n = zPlot->n = ref->n;
+    KapaSetLimits(kapa2, &graphdata);
+
+    psStats *stats = psStatsAlloc(PS_STAT_SAMPLE_MEDIAN);
+    psVectorStats (stats, zPlot, NULL, NULL, 0);
+    float zero = stats->sampleMedian + 3.0;
+    float range = 6.0;
+
+    for (int i = 0; i < zPlot->n; i++) {
+	float value = (zero - zPlot->data.F32[i]) / range;
+	zPlot->data.F32[i] = PS_MAX(0.0, PS_MIN(1.0, value));
+    }
+
+    // the point size will be scaled from the z vector
+    graphdata.style = 2;
+    graphdata.ptype = 7;
+    graphdata.size = -1;
+    graphdata.color = KapaColorByName ("black");
+
+    KapaPrepPlot   (kapa2, xPlot->n, &graphdata);
+    KapaPlotVector (kapa2, xPlot->n, xPlot->data.F32, "x");
+    KapaPlotVector (kapa2, yPlot->n, yPlot->data.F32, "y");
+    KapaPlotVector (kapa2, zPlot->n, zPlot->data.F32, "z");
+
+    // plot the RAW data (keep previous limits)
+    for (int i = 0; i < raw->n; i++) {
+        pmAstromObj *obj = raw->data[i];
+	xPlot->data.F32[i] = obj->FP->x;
+	yPlot->data.F32[i] = obj->FP->y;
+	zPlot->data.F32[i] = obj->Mag;
+    }
+    xPlot->n = yPlot->n = zPlot->n = raw->n;
+
+    psStatsInit(stats);
+    psVectorStats (stats, zPlot, NULL, NULL, 0);
+    zero = stats->sampleMedian + 3.0;
+    range = 6.0;
+
+    for (int i = 0; i < zPlot->n; i++) {
+	float value = (zero - zPlot->data.F32[i]) / range;
+	zPlot->data.F32[i] = PS_MAX(0.0, PS_MIN(1.0, value));
+    }
+
+    // the point size will be scaled from the z vector
+    graphdata.style = 2;
+    graphdata.ptype = 7;
+    graphdata.size = -1;
+    graphdata.color = KapaColorByName ("red");
+
+    KapaPrepPlot   (kapa2, xPlot->n, &graphdata);
+    KapaPlotVector (kapa2, xPlot->n, xPlot->data.F32, "x");
+    KapaPlotVector (kapa2, yPlot->n, yPlot->data.F32, "y");
+    KapaPlotVector (kapa2, zPlot->n, zPlot->data.F32, "z");
+
+    pmVisualAskUser(&plotGridMatch);
+    psFree(xPlot);
+    psFree(yPlot);
+    psFree(zPlot);
+    psFree(stats);
+    return true;
+}
 
 bool pmAstromVisualPlotTweak (psVector *xHist, // Smoothed Horizontal cut through the histogram