Hi Jiim, Thanks . I want to do the following: 1. each time I need to drop one column, say first column 1 from matrix X. 2 then take out row 1 of the remainning matrix and that row becomes response (y) 3. do lasso regression on remaining X to y. 4. store the coefficients
Similarly, in next run 1. I need to drop 2nd column, from matrix X. 2 then take out row 2 of the remainning matrix and that row becomes response (y) 3. do lasso regression on remaining X ( in example: X2to y.) 4. store the coefficients repeat On Sat, Jun 13, 2009 at 7:19 PM, jim holtman <jholt...@gmail.com> wrote: > It is not exactly clear what you want to iterate on. What is going to be > changing each time through the loop? > > On Sat, Jun 13, 2009 at 10:09 AM, Alex Roy <alexroy2...@gmail.com>wrote: > >> Dear all, >> I want to do the following process as a loop ( to run >> automatically with dimension of X, here 50). How can I do that? Your >> cooments will be highly appreciable. >> >> Alex >> >> >> *# Code:* >> >> library(lars) >> library(chemometrics) >> >> X<-matrix(rnorm(2500),ncol=50) >> dim(X) >> # [1] 50 50 >> X1<-X[,2:dim(X)[2]] # I have taken out first column >> dim(X1) >> #[1] 50 49 >> X2<-X1[2:dim(X1)[1],] # new X2 is constructed >> dim(X2) >> #[1] 49 49 >> y<-as.matrix(X1[1,]) # Now first row of the X1 acts a response vector >> dim(y) >> # [1] 49 1 >> >> # application of LASSO regression where y is response and X2 is a design >> matrix >> >> data1<-data.frame(y,X2=I(X2)) >> >> lasso_res=lassoCV(y~X2,data=data1,K=10,fraction=seq(0.1,1,by=0.1),use.Gram=FALSE) >> # to get optimum value of Cross Validation >> lasso_coef=lassocoef(y~X2,data=data1,sopt=lasso_res$sopt,use.Gram=FALSE) >> # >> to get the coefficients >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > > > > -- > Jim Holtman > Cincinnati, OH > +1 513 646 9390 > > What is the problem that you are trying to solve? > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.
