R Under development (unstable) (2023-11-28 r85645 ucrt) -- "Unsuffered Consequences"
Copyright (C) 2023 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> RSquared<-function(pred,true){
+ 	# Pierre Gramme
+ 	# Jan 2015
+ 	# Compute the R-squared coefficient of determination
+ 	
+ 	ss_tot = sum((true-mean(true)) ^ 2)
+ 	ss_res = sum((true-pred) ^ 2)
+   return(1 - ss_res/ss_tot)
+ }
> 
> 
> proc.time()
   user  system elapsed 
   0.17    0.09    0.25