Have a look this website

http://www.maths.bath.ac.uk/~jjf23/LMR/errata.html

p139, package pls.pcr has been replaced with package pls in more recent versions of R. Last paragraph is now: The pls package can compute this CV. By default, the data is divided into ten parts for the CV: > pcrmod <- pcr(fat ~ ., data=meatspec[1:172,], validation="CV",ncomp=50)> validationplot(pcrmod)p140, validationplot() above produces a slightly different plot for the right panel of Figure 9.5. p141, The plsr() function now centers the predictors internally. So first sentence can now read "We now compute the PLS on all models up to size 50". The next chunk of R code becomes: > plsg <- plsr(fat ~ ., data=meatspec[1:172,], ncomp=50, validation="CV")> coefplot(plsg,ncomp=4,xlab="Frequency")> validationplot(plsg)The centering described in the last two sentences of p141 is now redundant. Last chunk of R code becomes: > ypred <- predict(plsg,ncomp=14)> rmse(ypred,meatspec$fat[1:172])p142, chunk of R code becomes: > ytpred <- predict(plsg,meatspec[173:215,],ncomp=14)> rmse(ytpred,meatspec$fat[173:215])Note also that Figure 9.7 is somewhat changed by using the plotting functions from the pls package.

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