Thanks Rolf and Arun! -David On Wed, Feb 6, 2013 at 6:13 AM, arun <smartpink...@yahoo.com> wrote:
> Hi, > > I got an error message with: > vlist <- apply(mm, list) > > Error in match.fun(FUN) : argument "FUN" is missing, with no default > #assuming that > vlist <- apply(mm,2,list) > > mapply("%*%",mlist,vlist[1:2],SIMPLIFY=FALSE) > #[[1]] > # [,1] > #[1,] 19 > #[2,] 22 > #[3,] 25 > #[4,] 28 > # > #[[2]] > # [,1] > #[1,] 67 > #[2,] 74 > #[3,] 81 > #[4,] 88 > > A.K. > ----- Original Message ----- > From: David Romano <drom...@stanford.edu> > To: r-help@r-project.org > Cc: > Sent: Wednesday, February 6, 2013 12:50 AM > Subject: [R] how to "multiply" list of matrices by list of vectors > > Hi everyone, > > I'd like to be able to apply lda to each 2D matrix slice of a 3D array, and > then use the scalings to obtain the corresponding lda scores. > > I can use 'apply' to get a list of the lda output for each 2D slice, and > can create a list of the resulting scalings, but I'm not sure how to > multiply them in a vectorized way. > > > Here's how I made a list of 2D matrices (suggestion on improving this would > be welcome, too!): > > > aa <- array(1:24,c(4,2,3)) > > mlist <- apply(aa,2,list) > > mlist <- lapply(mlist, unlist) > > mlist <- lapply(mlist, function(x) matrix(x,4,2)) > > and here's how I made a list of vectors: > > > mm <- matrix(1:6,2,3) > > vlist <- apply(mm, list) > > vlist <- lapply(vlist, unlist) > > Now I'd like to make the list whose i-th element is mlist[[i]]%*%vlist[[i]] > without having to loop through the indices. > > Any help would be appreciated! > > Thanks, > David > > [[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. > > [[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.