Per #1843, check for divide by zero when computing SI... this could h…

…appen if comparing the same input file to itself with Grid-Stat.

met/src/libcode/vx_statistics/compute_stats.cc

@@ -121,7 +121,12 @@ void compute_cntinfo(const SL1L2Info &s, bool aflag, CNTInfo &cnt_info) {
    cnt_info.rmse.v = sqrt(cnt_info.mse.v);
 
    // Compute Scatter Index (SI)
-   cnt_info.si.v = cnt_info.rmse.v / cnt_info.me.v;
+   if(!is_eq(cnt_info.me.v, 0.0)) {
+      cnt_info.si.v = cnt_info.rmse.v / cnt_info.me.v;
+   }
+   else {
+      cnt_info.si.v = bad_data_double;
+   }
 
    // Compute normal confidence intervals
    cnt_info.compute_ci();
@@ -348,7 +353,13 @@ void compute_cntinfo(const PairDataPoint &pd, const NumArray &i_na,
    //
    // Compute Scatter Index (SI)
    //
-   cnt_info.si.v = cnt_info.rmse.v / cnt_info.me.v;
+   if(!is_eq(cnt_info.me.v, 0.0)) {
+      cnt_info.si.v = cnt_info.rmse.v / cnt_info.me.v;
+   }
+   else {
+      cnt_info.si.v = bad_data_double;
+   }
+
 
    //
    // Only compute the Kendall Tau and Spearman's Rank corrleation