Index: trunk/psphot/src/psphotPetrosianRadialBins.c
===================================================================
--- trunk/psphot/src/psphotPetrosianRadialBins.c	(revision 28013)
+++ trunk/psphot/src/psphotPetrosianRadialBins.c	(revision 31154)
@@ -51,4 +51,5 @@
     psVector *binRad  	 = psVectorAllocEmpty(nMax, PS_TYPE_F32); // mean radius of radial bin
     psVector *binArea 	 = psVectorAllocEmpty(nMax, PS_TYPE_F32); // area of radial bin (contiguous, non-overlapping)
+    psVector *binFill 	 = psVectorAllocEmpty(nMax, PS_TYPE_F32); // fraction of radial bin with valid pixels
 
     psVectorInit (binSB, 0.0);
@@ -144,4 +145,5 @@
 	    binSB->data.F32[nOut] = value;
 	    binSBstdev->data.F32[nOut] = sqrt(PS_SQR(dvalue) / values->n + skyModelErrorSQ);
+	    binFill->data.F32[nOut] = values->n / binArea->data.F32[nOut];
 
 	    // error in the SB is the stdev per bin / sqrt (number of pixels) 
@@ -176,4 +178,5 @@
 	psFree(binRad);
 	psFree(binArea);
+	psFree(binFill);
 	psFree(radMin);
 	psFree(radMax);
@@ -202,8 +205,10 @@
     psFree(profile->radialBins);
     psFree(profile->area);
+    psFree(profile->binFill);
 
     // save the vectors
     profile->radialBins = binRad;
     profile->area       = binArea;
+    profile->binFill    = binFill;
     profile->binSB      = binSB;
     profile->binSBstdev = binSBstdev;