Index: /branches/eam_branch_20070921/psphot/src/psphot.h
===================================================================
--- /branches/eam_branch_20070921/psphot/src/psphot.h	(revision 14994)
+++ /branches/eam_branch_20070921/psphot/src/psphot.h	(revision 14995)
@@ -47,5 +47,5 @@
 bool            psphotReplaceAll (psArray *sources, psMaskType maskVal);
 bool            psphotApResid (pmReadout *readout, psArray *sources, psMetadata *recipe, pmPSF *psf, psMaskType maskVal, psMaskType mark);
-bool            psphotMagErrorScale (float *errorScale, float *errorFloor, psVector *dMag, psVector *dap, int nGroup);
+bool            psphotMagErrorScale (float *errorScale, float *errorFloor, psVector *dMag, psVector *dap, psVector *mask, int nGroup);
 bool            psphotApResidTrend (pmReadout *readout, pmPSF *psf, int Npsf, int scale, float *errorScale, float *errorFloor, psVector *mask, psVector *xPos, psVector *yPos, psVector *apResid, psVector *dMag);
 bool            psphotMagnitudes (psArray *sources, psMetadata *recipe, pmPSF *psf, pmReadout *background, psMaskType maskVal, psMaskType mark);
Index: /branches/eam_branch_20070921/psphot/src/psphotApResid.c
===================================================================
--- /branches/eam_branch_20070921/psphot/src/psphotApResid.c	(revision 14994)
+++ /branches/eam_branch_20070921/psphot/src/psphotApResid.c	(revision 14995)
@@ -103,4 +103,5 @@
         dMag->data.F32[Npsf] = model->dparams->data.F32[PM_PAR_I0] / model->params->data.F32[PM_PAR_I0];
 
+        psVectorExtend (mag,     100, 1);
         psVectorExtend (mask,    100, 1);
         psVectorExtend (xPos,    100, 1);
@@ -157,6 +158,4 @@
     psVector *apResidRes = (psVector *) psBinaryOp (NULL, (void *) apResid, "-", (void *) apResidFit);
     psVector *dMagSys = (psVector *) psBinaryOp (NULL, (void *) dMag, "*", (void *) psScalarAlloc(errorScale, PS_TYPE_F32));
-
-    psphotSaveImage (NULL, psf->ApTrend->map->map, "apresid.map.fits");
 
     if (psTraceGetLevel("psphot") >= 5) {
@@ -212,5 +211,5 @@
 */
 
-bool psphotMagErrorScale (float *errorScale, float *errorFloor, psVector *dMag, psVector *dap, int nGroup) {
+bool psphotMagErrorScale (float *errorScale, float *errorFloor, psVector *dMag, psVector *dap, psVector *mask, int nGroup) {
 
     psStats *statsS = psStatsAlloc (PS_STAT_ROBUST_MEDIAN | PS_STAT_ROBUST_STDEV);
@@ -231,4 +230,5 @@
     psVector *dMSubset = psVectorAllocEmpty (nGroup, PS_TYPE_F32);
     psVector *dASubset = psVectorAllocEmpty (nGroup, PS_TYPE_F32);
+    psVector *mkSubset = psVectorAllocEmpty (nGroup, PS_TYPE_U8);
 
     int n = 0;
@@ -239,13 +239,15 @@
 	    dMSubset->data.F32[j] = dMag->data.F32[N];
 	    dASubset->data.F32[j] = dap->data.F32[N];
+	    mkSubset->data.U8[j]  = mask->data.U8[N];
 	}
 	dMSubset->n = j;
 	dASubset->n = j;
+	mkSubset->n = j;
 
 	psStatsInit (statsS);
 	psStatsInit (statsM);
 
-	psVectorStats (statsS, dASubset, NULL, NULL, 0xff);
-	psVectorStats (statsM, dMSubset, NULL, NULL, 0xff);
+	psVectorStats (statsS, dASubset, NULL, mkSubset, 0xff);
+	psVectorStats (statsM, dMSubset, NULL, mkSubset, 0xff);
 
 	dSo->data.F32[i] = statsS->robustStdev;
@@ -256,4 +258,5 @@
     psFree (dMSubset);
     psFree (dASubset);
+    psFree (mkSubset);
     
     psStats *stats = psStatsAlloc (PS_STAT_SAMPLE_MEDIAN);
@@ -292,4 +295,7 @@
     }
 
+    // the mask marks the values not used to calculate the ApTrend
+    psVectorInit (mask, 0);
+
     // XXX stats structure for use by ApTrend : make parameters user setable
     psStats *stats = psStatsAlloc (PS_STAT_ROBUST_MEDIAN | PS_STAT_ROBUST_STDEV);
@@ -311,5 +317,5 @@
     // XXX this is a bit arbitrary, but it forces ~3 stars from the bright bin per spatial bin
     int nGroup = PS_MAX (3*Nx*Ny, 10);
-    psphotMagErrorScale (errorScale, errorFloor, dMag, apResidRes, nGroup);
+    psphotMagErrorScale (errorScale, errorFloor, dMag, apResidRes, mask, nGroup);
 
     psLogMsg ("psphot.apresid", PS_LOG_INFO, "result of %d x %d grid (%d stars per bin)\n", Nx, Ny, nGroup);