From 7e3cd680ee28895ec97ab3242ce23f7ac03ab024 Mon Sep 17 00:00:00 2001
From: Joakim Skogholt <onlinereg@skogholt.xyz>
Date: Fri, 24 May 2024 19:04:37 +0200
Subject: [PATCH] La til funksjon for utregning av RMSE

---
 src/Ting.jl                       |  1 +
 src/variousRegressionFunctions.jl | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/src/Ting.jl b/src/Ting.jl
index 31f7471..f5f92f3 100644
--- a/src/Ting.jl
+++ b/src/Ting.jl
@@ -30,6 +30,7 @@ export TRLooCVUpdateNaive
 export TRLooCVUpdateExperimental
 
 # From "variousRegressionFunctions.jl"
+export calculateRMSE
 export oldRegCoeffs
 export PCR
 export PLS
diff --git a/src/variousRegressionFunctions.jl b/src/variousRegressionFunctions.jl
index c500a19..9932b4c 100644
--- a/src/variousRegressionFunctions.jl
+++ b/src/variousRegressionFunctions.jl
@@ -1,3 +1,22 @@
+"""
+function rmse, ypred = calculateRMSE(X, y, beta)
+
+Regner ut RMSE for lineær regresjonsmodell med eller uten konstantledd.
+(Konstantledd må være første element i beta hvis med)    
+"""
+
+function calculateRMSE(X, y, beta)
+
+if length(beta) == size(X,2)
+    ypred = X * beta;
+elseif length(beta) == (size(X,2) +  1)
+    ypred = beta[1] .+ X * beta[2:end]
+end
+
+rmsep = sqrt(mean(y - ypred).^2)
+
+return rmse, ypred
+end