From db7d88b1fd2096de67cd75afdf7954cdb95e6bb7 Mon Sep 17 00:00:00 2001
From: Jaap van Ekris <82339657+JaapvanEkris@users.noreply.github.com>
Date: Mon, 8 Jan 2024 12:02:56 +0100
Subject: [PATCH] implemented the Goodness of Fit indicator

---
 app/engine/utils/FullTSLinearSeries.js | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/app/engine/utils/FullTSLinearSeries.js b/app/engine/utils/FullTSLinearSeries.js
index e4464f5..9db538b 100644
--- a/app/engine/utils/FullTSLinearSeries.js
+++ b/app/engine/utils/FullTSLinearSeries.js
@@ -31,7 +31,6 @@ function createTSLinearSeries (maxSeriesLength = 0) {
 
   let _A = 0
   let _B = 0
-  let _goodnessOfFit = 0
 
   function push (x, y) {
     // Invariant: A contains all a's (as in the general formula y = a * x^2 + b * x + c)
@@ -88,8 +87,21 @@ function createTSLinearSeries (maxSeriesLength = 0) {
 
   function goodnessOfFit () {
     // This function returns the R^2 as a goodness of fit indicator
+    let i = 0
+    let ssr = 0
+    let sst = 0
     if (X.length() >= 2) {
-      return _goodnessOfFit
+      while (i < X.length() - 1) {
+        ssr =+ Math.pow((Y.get(i) - projectX(X.get(i))), 2)
+        sst =+ Math.pow((Y.get(i) - Y.average()), 2)
+        i++
+      }
+      if (sst !== 0) {
+        const _goodnessOfFit = 1 - (ssr / sst)
+        return _goodnessOfFit
+      } else {
+        return 0
+      }
     } else {
       return 0
     }
@@ -174,7 +186,6 @@ function createTSLinearSeries (maxSeriesLength = 0) {
     A.reset()
     _A = 0
     _B = 0
-    _goodnessOfFit = 0
   }
 
   return {