R Under development (unstable) (2023-12-09 r85665 ucrt) -- "Unsuffered Consequences"
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> 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 
   0.15    0.07    0.21