While running the following line
tune.rcc(X, Y, grid1 = grid1, grid2 = grid2, validation = "Mfold")
I got the following warning:
Calls: tune.rcc -> apply -> FUN -> Mfold -> rcc -> explained_variance
Warning in explained_variance(result$Y, result$variates$Y, ncomp) :
NA values put to zero, results will differ from PCA methods
used with NIPALS
does it mean the NAs were filled with zero?