Comparing "R-PLS", "CARET" and "WIN ISI"

I made this exercise just for fun. When we develop a regression we don´t have to look the the XY plot where a sample is predicted from a model where this sample is already included, we have to compare it against a model where she is excluded. So we have to look to see how the samples fits to the regression line to the XY plot of Cross Validation for the number of terms we have selected for the final model.

 

In this case I develop the comparison for a regression of protein in fish meal with the 40 samples I am using in the series of tutorials about "Tidyverse and Chemometrics" using the PLS  and Caret packages and also Win ISI (FOSS Analytical Chemometric software).

 

PLS, Win ISI and Caret recommend 8 terms and as you can see they gave the same LOO Cross Validation XY plots or very similar. Remember that these are the XY plots of predictions where every sample is predicted with the 39 remaining so it´s more realistic of how it will performs in routine.