Hi,
Newbie question about the pls package.
Setup:
Mac OS 10.3.9
R: Aqua GUI 1.01, v 2.0.1
I want to get R^2 and Q^2 (LOO and Leave-10-Out) values for each
component for my model.
I was running into a few problems so I played with the example a little
and the results do not match up with the comments
in the help pages.
$ library(pls)
$ data(NIR)
$ testing.plsNOCV <- plsr(y ~ X, 6, data = NIR, method="kernelpls",
validation="none")
$ NIR.plsCV <- plsr(y ~ X, 6, data = NIR, CV=TRUE, method="kernelpls")
$ testing.plsCV <- crossval(testing.plsNOCV)
$ R2(NIR.plsCV)
(Intercept) 1 comps 2 comps 3 comps 4 comps 5
comps
0.0000 0.9812 0.9825 0.9964 0.9997
0.9999
6 comps
0.9999
$ R2(testing.plsCV)
(Intercept) 1 comps 2 comps 3 comps 4 comps 5
comps
0.0000 0.9678 0.9782 0.9941 0.9991
0.9996
6 comps
0.9997
$ ?crossval
"This function performs cross-validation on a model fit by mvr. It can
handle models such as plsr(y ~ msc(X), ...) or other models where the
predictor variables need to be recalculated for each segment. When
recalculation is not needed, the result of crossval(mvr(...)) is
identical to mvr(..., CV = TRUE), but slower."
If the above result is correct can someone explain the difference to me.
Using the above scheme gives different results for my model (dim(X) ~
88 x 1500), of around ~ 0.2 (7th Comp) in R2, and so the question is
which one should I use?
Your help will be greatly appreciated,
Cheers,
Martin.
[[alternative text/enriched version deleted]]
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