From 2c13f4a5a2853df2d3af0be7b5833b447143e704 Mon Sep 17 00:00:00 2001
From: Seth Linden <linden@seneca.rap.ucar.edu>
Date: Wed, 7 Sep 2022 14:34:50 -0600
Subject: [PATCH] Per issue #2206, added new function
 weighted_mean_absolute_diff(). SL

---
 src/basic/vx_util/num_array.cc | 80 ++++++++++++++++++++++------------
 src/basic/vx_util/num_array.h  |  1 +
 2 files changed, 52 insertions(+), 29 deletions(-)

diff --git a/src/basic/vx_util/num_array.cc b/src/basic/vx_util/num_array.cc
index d4f3a86a35..8cec3bef2d 100644
--- a/src/basic/vx_util/num_array.cc
+++ b/src/basic/vx_util/num_array.cc
@@ -1233,24 +1233,29 @@ double NumArray::stdev(int skip_index) const
 
 ////////////////////////////////////////////////////////////////////////
 
-//
-//  Utility Functions
-//
-
-////////////////////////////////////////////////////////////////////////
 
-
-ConcatString write_css(const NumArray &na)
+double NumArray::mean_abs_diff() const
 
 {
 
-   ConcatString css;
+   int i, j, count;
+   double sum, mad;
 
-   for ( int i=0; i<na.n_elements(); ++i ) {
-      css << (i == 0 ? "" : ",") << na[i];
+   int n = n_elements();
+   
+   for(i=0, count=0, sum=0.0; i<n; i++) {
+      for(j=i+1; j<n; j++) {
+      
+         if( is_bad_data(e[i]) || is_bad_data(e[j]) ) continue;
+         sum += abs(e[i]-e[j]);
+         count++;
+      }
    }
+      
+   if(count == 0) mad = bad_data_double;
+   else           mad = sum / (n*(n-1));
 
-   return(css);
+   return(mad);
 
 }
 
@@ -1258,14 +1263,42 @@ ConcatString write_css(const NumArray &na)
 ////////////////////////////////////////////////////////////////////////
 
 
-ConcatString write_css_hhmmss(const NumArray &na)
+double NumArray::weighted_mean_abs_diff() const
+
+{
+
+   double mad, weighted_mad;
+   
+   int n = n_elements();
+   
+   mad = mean_abs_diff();
+   
+   if( is_bad_data(mad) )
+      weighted_mad = bad_data_double;
+   else
+      weighted_mad = (1/(2*n)) * mad;
+   
+   return(weighted_mad);
+
+}
+
+////////////////////////////////////////////////////////////////////////
+
+//
+//  Utility Functions
+//
+
+////////////////////////////////////////////////////////////////////////
+
+
+ConcatString write_css(const NumArray &na)
 
 {
 
    ConcatString css;
 
    for ( int i=0; i<na.n_elements(); ++i ) {
-      css << (i == 0 ? "" : ",") << sec_to_hhmmss(na[i]);
+      css << (i == 0 ? "" : ",") << na[i];
    }
 
    return(css);
@@ -1276,28 +1309,17 @@ ConcatString write_css_hhmmss(const NumArray &na)
 ////////////////////////////////////////////////////////////////////////
 
 
-double NumArray::mean_abs_diff() const
+ConcatString write_css_hhmmss(const NumArray &na)
 
 {
 
-   int i, j, count;
-   double sum, mad;
+   ConcatString css;
 
-   int n = n_elements();
-   
-   for(i=0, count=0, sum=0.0; i<n; i++) {
-      for(j=i+1; j<n; j++) {
-      
-         if( is_bad_data(e[i]) || is_bad_data(e[j]) ) continue;
-         sum += abs(e[i]-e[j]);
-         count++;
-      }
+   for ( int i=0; i<na.n_elements(); ++i ) {
+      css << (i == 0 ? "" : ",") << sec_to_hhmmss(na[i]);
    }
-      
-   if(count == 0) mad = bad_data_double;
-   else           mad = sum / (n*(n-1));
 
-   return(mad);
+   return(css);
 
 }
 
diff --git a/src/basic/vx_util/num_array.h b/src/basic/vx_util/num_array.h
index bc962d7e48..275dc2991b 100644
--- a/src/basic/vx_util/num_array.h
+++ b/src/basic/vx_util/num_array.h
@@ -110,6 +110,7 @@ class NumArray {
       double mean_sqrt() const;
       double mean_fisher() const;
       double mean_abs_diff() const;
+      double weighted_mean_abs_diff() const;
       
       double variance(int skip_index = bad_data_int) const;
       double stdev(int skip_index = bad_data_int) const;