Index: /trunk/psModules/src/imcombine/pmReadoutCombine.c
===================================================================
--- /trunk/psModules/src/imcombine/pmReadoutCombine.c	(revision 10775)
+++ /trunk/psModules/src/imcombine/pmReadoutCombine.c	(revision 10776)
@@ -363,4 +363,5 @@
             }
 
+            // XXXXX this step probably is very expensive : convert errors to variance everywhere?
             if (params->weights) {
                 errors = (psVector*)psUnaryOp(errors, weights, "sqrt");
@@ -373,4 +374,6 @@
                 float stdev = psStatsGetValue(stats, combineStdev);
                 outputWeight[yOut][xOut] = PS_SQR(stdev); // Variance
+                // XXXX this is not the correct formal error.
+                // also, the weighted mean is not obviously the correct thing here
             }
         }