Index: trunk/psModules/src/astrom/pmAstrometryVisual.c
===================================================================
--- trunk/psModules/src/astrom/pmAstrometryVisual.c	(revision 35768)
+++ trunk/psModules/src/astrom/pmAstrometryVisual.c	(revision 36834)
@@ -946,5 +946,5 @@
     KapaSendLabel (kapa2, "X (FP)", KAPA_LABEL_XM);
     KapaSendLabel (kapa2, "Y (FP)", KAPA_LABEL_YM);
-    KapaSendLabel (kapa2, "pmAstromGridAngle residuals. Box: Correlation Peak.", KAPA_LABEL_XP);
+    KapaSendLabel (kapa2, "pmAstromGridAngle red: raw, black: ref.", KAPA_LABEL_XP);
 
     // plot the REF data.  (also calculate the plot ranges, accumulate the plot vectors)
@@ -966,13 +966,18 @@
     KapaSetLimits(kapa2, &graphdata);
 
-    psStats *stats = psStatsAlloc(PS_STAT_SAMPLE_MEDIAN);
+    psStats *stats = psStatsAlloc(PS_STAT_SAMPLE_MEDIAN | PS_STAT_MIN  | PS_STAT_MAX );
     psVectorStats (stats, zPlot, NULL, NULL, 0);
-    float zero = stats->sampleMedian + 3.0;
-    float range = 6.0;
-
+    float range = stats->max - stats->min;
+    range = PS_MAX (0.5, PS_MIN (6.0, range));
+    float zero = stats->sampleMedian + 0.25*range;
+
+    float maxZ = zPlot->data.F32[0], minZ = zPlot->data.F32[0];
     for (int i = 0; i < zPlot->n; i++) {
+	maxZ = PS_MAX (maxZ, zPlot->data.F32[i]);
+	minZ = PS_MIN (minZ, zPlot->data.F32[i]);
 	float value = (zero - zPlot->data.F32[i]) / range;
 	zPlot->data.F32[i] = PS_MAX(0.0, PS_MIN(1.0, value));
     }
+    fprintf (stderr, "ref mags: %f to %f (%f median)\n", minZ, maxZ, stats->sampleMedian);
 
     // the point size will be scaled from the z vector
@@ -998,11 +1003,18 @@
     psStatsInit(stats);
     psVectorStats (stats, zPlot, NULL, NULL, 0);
-    zero = stats->sampleMedian + 3.0;
-    range = 6.0;
-
+    range = stats->max - stats->min;
+    range = PS_MAX (0.5, PS_MIN (6.0, range));
+    zero = stats->sampleMedian + 0.25*range;
+    // zero = stats->sampleMedian + 1.0;
+    // range = 6.0;
+
+    maxZ = zPlot->data.F32[0], minZ = zPlot->data.F32[0];
     for (int i = 0; i < zPlot->n; i++) {
+	maxZ = PS_MAX (maxZ, zPlot->data.F32[i]);
+	minZ = PS_MIN (minZ, zPlot->data.F32[i]);
 	float value = (zero - zPlot->data.F32[i]) / range;
 	zPlot->data.F32[i] = PS_MAX(0.0, PS_MIN(1.0, value));
     }
+    fprintf (stderr, "raw mags: %f to %f (%f median)\n", minZ, maxZ, stats->sampleMedian);
 
     // the point size will be scaled from the z vector