Index: trunk/psphot/src/psphotApResid.c
===================================================================
--- trunk/psphot/src/psphotApResid.c	(revision 15040)
+++ trunk/psphot/src/psphotApResid.c	(revision 15042)
@@ -285,8 +285,8 @@
     if (readout->image->numCols > readout->image->numRows) {
 	Nx = scale;
-	Ny = PS_MAX (1, Nx * (readout->image->numRows / readout->image->numCols));
+	Ny = PS_MAX (1, Nx * (readout->image->numRows / (float) readout->image->numCols));
     } else {
 	Ny = scale;
-	Nx = PS_MAX (1, Ny * (readout->image->numCols / readout->image->numRows));
+	Nx = PS_MAX (1, Ny * (readout->image->numCols / (float) readout->image->numRows));
     }