Index: /trunk/Ohana/src/opihi/lib.data/mrqmin.c
===================================================================
--- /trunk/Ohana/src/opihi/lib.data/mrqmin.c	(revision 4303)
+++ /trunk/Ohana/src/opihi/lib.data/mrqmin.c	(revision 4304)
@@ -51,4 +51,5 @@
   int j, k;
   float chisq;
+  float rho, dX, dL;
 
   /* set up test matrixes for this run */
@@ -63,4 +64,10 @@
   for (j = 0; j < Npar; j++) partry[j] = par[j] - tbeta[j][0];
 
+  /* get linear model prediction */
+  dL = 0;
+  for (j = 0; j < Npar; j++) {
+      dL += 0.5*lambda*SQ(tbeta[j][0]) + tbeta[j][0]*beta[j][0];
+  }
+
   chisq = mrqcof (x, y, dy, Npts, partry, Npar, talpha, tbeta, funcs);
   if (VERBOSE) { 
@@ -73,6 +80,10 @@
   }
 
+  /* compare linear model with actual */
+  dX = ochisq - chisq;
+  rho = dX / dL;
+
   /* if good, save temp values */
-  if (chisq < ochisq) {
+  if (rho > 0) {
     lambda *= 0.1;
     ochisq = chisq;