Hi Ron, Here you go.
Cheers, Josh dat <- matrix(1:9,3) ldat <- list(dat, dat, dat) ldat[[1]] == dat ## Or lapply(1:3, function(x) dat) ## which is similar in spirit to output <- vector("list", 3) for(i in 1:3) { output[[i]] <- dat } list1 <- list2 <- vector("list", length=2) for(i in 1:2) { list1[[i]] <- matrix(rnorm(15), 3) list2[[i]] <- matrix(rnorm(15), 3) } lapply(1:2, function(x) {list1[[x]] + list2[[x]]}) ## This can be done more simply lapply(1:2, function(x) {matrix(rnorm(15), 3) + matrix(rnorm(15), 3)}) On Sat, Jan 8, 2011 at 3:26 AM, Ron Michael <ron_michae...@yahoo.com> wrote: > Hi, I have 2 questions on list object: > > 1. Suppose I have a matrix like: > dat <- matrix(1:9,3) > > Now I want to replicate this entire matrix 3 times and put entire result in a > list object. Means, if "res" is the resulting list then I should have: > > res[[1]]=dat, res[[2]]=dat, res[[3]]=dat > > How can I do that in the easilest manner? > > 2. Suppose I have 2 list objects: > list1 <- list2 <- vector("list", length=2) > for(i in 1:2) { > list1[[i]] <- matrix(rnorm(15), 3) > list2[[i]] <- matrix(rnorm(15), 3) > } > > How can I add these 2 list objects? I have tried with just list1+list2, > however it is generating some error. > > Would be grateful for any help. > > Thanks, > > > [[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. > > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ 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.