> On Jan 14, 2016, at 2:33 AM, CG Pettersson <cg.petters...@lantmannen.com> > wrote: > > Dear Jeff, > thanks for the effort, but the use of I() when preparing the dataset is > suggested by the authors (Mevik & Wehrens, section 3.2): > > +If Z is a matrix, it has to be protected by the ‘protect function’ I() in > calls > +to data.frame: mydata <- data.frame(..., Z = I(Z)). Otherwise, it will be > split into > +separate variables for each column, and there will be no variable called Z > in the data frame, > +so we cannot use Z in the formula. One can also add the matrix to an > existing data frame: > +R> mydata <- data.frame(...) > +R> mydata$Z <- Z > > In the dataset "gasoline" that is supplied with the pls package, there are > two variables; octane and NIR, where NIR is a frame with 401 columns and > possible to work with like: > plsr(octane ~NIR, data = gasoline) > I thought "gasoline" was made like the example above, but I must be missing > something else. > > Whatever I do ends with " invalid type (list) for variable 'n96'"
Was `n96` a list before you put a copy of it into the `frame1`-object? Maybe it wasn't a simple matrix. You need at the very least to post the output of str(n96). Also .... never use attach(). -- David. > > So I am still stuck > /CG > > Från: Jeff Newmiller [mailto:jdnew...@dcn.davis.ca.us] > Skickat: den 14 januari 2016 05:16 > Till: CG Pettersson; r-help@r-project.org > Ämne: Re: [R] Problems with data structure when using plsr() from package pls > > Using I() in the data.frame seems ill-advised to me. You complain about 96 > variables but from reading your explanation that seems to be what your data > are. I have no idea whether it makes sense to NOT have 96 variables if that > is what your data are. Note that a reproducible example supplied by you might > help us guess better, but it might just be that your expectations are wrong. > -- > Sent from my phone. Please excuse my brevity. > On January 13, 2016 11:02:25 AM PST, CG Pettersson > <cg.petters...@lantmannen.com> wrote: > R version 3.2.3, W7 64bit. > > Dear all! > > 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)) > > Where gushVM is a vector with fifteen reference analysis values of a quality > problem in grain and n96 is a matrix with fifteen rows and 96 columns from an > electronic nose. I try to copy the methods as in 3.2 in Mevik & Wehrens, and > want to keep n96 as one variable to avoid addressing 96 different variables > in the plsr call. If I don�t use I() in the call I get 96 variables instead. > Looking at the data > frame by > summary(frame1) get a return quite like summary(gasoline) from the package > (not shown here). > But when I try to use plsr() with my own data it doesn�t work due to an error > in the data structure: > pls1 <- plsr(gushVM ~ n96, data = frame1) > Error in model.frame.default(formula = gushVM ~ n96, data = frame1) : > invalid type (list) for variable 'n96' > > So, n96 has turned into a list, and that is a problem. If gushVM is a vector > (one variable) och a matrix (five variables) does not seem to change > anything, managing n96 is the problem > I have tried all alternative ways of creating a proper data frame suggested > in the article with exactly the same result. > I have tried the docum > entation > for data.frame() but I probably don�t understand what it says. > > What should I do to change "n96" into something better than "list"? > > Thanks > /CG > > Med v�nlig h�lsning/Best regards > CG Pettersson > Scientific Project Manager, PhD > ______________________ > Lantm�nnen Corporate R&D > Phone: +46 10 556 19 85 > Mobile: + 46 70 330 66 85 > Email: cg.petters...@lantmannen.com<mailto:cg.petters...@lantmannen.com> > Visiting Address: S:t G�ransgatan 160 A > Address: Box 30192, SE-104 25 Stockholm > Webb: http://www.lantmannen.com<http://www.lantmannen.com/> > Registered Office: Stockholm > Before printing, think about the environment > > > [[alternative HTML version deleted]] > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. David Winsemius Alameda, CA, USA ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
