Index: /branches/eam_branches/20090715/psphot/src/psphotEllipticalProfile.c
===================================================================
--- /branches/eam_branches/20090715/psphot/src/psphotEllipticalProfile.c	(revision 25362)
+++ /branches/eam_branches/20090715/psphot/src/psphotEllipticalProfile.c	(revision 25363)
@@ -38,9 +38,9 @@
 	for (int ix = 0; ix < source->pixels->numCols; ix++) {
 
-	    float x = ix - source->peak->xf + source->pixels->col0;
-	    float y = iy - source->peak->yf + source->pixels->row0;
+	    // 0.5 PIX: get radius as a function of pixel coord
+	    float x = ix + 0.5 - source->peak->xf + source->pixels->col0;
+	    float y = iy + 0.5 - source->peak->yf + source->pixels->row0;
 
 	    float r2 = 0.5*PS_SQR(x/Sxx) + 0.5*PS_SQR(y/Syy) + x*y*Sxy;
-	    // float r2 = PS_SQR(x/Sxx) + PS_SQR(y/Syy) + x*y*Sxy;
 
 	    psVectorAppend(radius, sqrt(r2));