only divide by the old error if it is not zero

[[Imported from SVN: r2312]]

bin/solver-eoc.py

@@ -153,7 +153,7 @@ for i in range(fro,to):
     error = sqrt(current_iterate*A*current_iterate.transpose())
 
     # Compute the convergence rate
-    if (i!=fro):
+    if (i!=fro and old_error != 0):
         conv_rate = error / old_error
         conv_rate_product *= conv_rate