Per #1843, correct definition of SI from RMSE/ME to RMSE/OBAR.

dtcenter · Jul 29, 2021 · 76fa862 · 76fa862
1 parent 1d849fb
commit 76fa862
Show file tree

Hide file tree

Showing 2 changed files with 3 additions and 3 deletions.
diff --git a/met/docs/Users_Guide/appendixC.rst b/met/docs/Users_Guide/appendixC.rst
@@ -501,7 +501,7 @@ Scatter Index (SI)
 
 Called "SI" in CNT output :numref:`table_PS_format_info_CNT`
 
-SI is the ratio of the root mean squared error to the mean error (overall bias), :math:`\text{SI} = \text{RMSE} / \text{ME}`.
+SI is the ratio of the root mean squared error to the average observation value, :math:`\text{SI} = \text{RMSE} / \text{OBAR}`.
 
 Smaller values of SI indicate better agreement between the model and observations (less scatter on scatter plot).
 

diff --git a/met/src/libcode/vx_statistics/compute_stats.cc b/met/src/libcode/vx_statistics/compute_stats.cc
@@ -122,7 +122,7 @@ void compute_cntinfo(const SL1L2Info &s, bool aflag, CNTInfo &cnt_info) {
 
    // Compute Scatter Index (SI)
    if(!is_eq(cnt_info.me.v, 0.0)) {
-      cnt_info.si.v = cnt_info.rmse.v / cnt_info.me.v;
+      cnt_info.si.v = cnt_info.rmse.v / cnt_info.obar.v;
    }
    else {
       cnt_info.si.v = bad_data_double;
@@ -354,7 +354,7 @@ void compute_cntinfo(const PairDataPoint &pd, const NumArray &i_na,
    // Compute Scatter Index (SI)
    //
    if(!is_eq(cnt_info.me.v, 0.0)) {
-      cnt_info.si.v = cnt_info.rmse.v / cnt_info.me.v;
+      cnt_info.si.v = cnt_info.rmse.v / cnt_info.obar.v;
    }
    else {
       cnt_info.si.v = bad_data_double;