[R] Problems with data structure when using plsr() from package pls

[S Ellison]

> > I am trying to make pls-regression using plsr() from package pls, with
> > Mevik & Wehrens (2007) as tutorial and the datasets from the package.
> > Everything works real nice as long as I use the supplied datasets, but
> > I don´t understand how to prepare my own data.
> > This is what I have done:
> >
> > > frame1 <- data.frame(gushVM, I(n96))

Reading ?plsr examples and inspecting the data they use, you need to arrange frame1 so that it has the data from n96 included as columns with names of the from "n96.xxx" whre xxx can be numbers, names etc.

If n96 is a data frame, try something like
names(n96) <- paste("n96", 1:96) 
frame1 <- cbind(gushVM, n96)

pls1 <- plsr(gushVM ~ n96, data = frame1)


If n96 is a matrix, 

frame1 <- data.frame(gushVM, n96=n96)

should also give you a data frame with names of the right format.

I() wrapped round a matrix or data frame does nothing like what is needed if you include it in a data frame construction, so either things have changed since the tutorial was written, or the authors were not handling a matrix or data frame with I().

S Ellison






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