Thanks for your suggestions. I need one more thing : x = y = vector("list") for (i in 1:5) x[[i]] = rnorm(2); y[[i]] = rnorm(2)
Here I want to get t(x[[i]]) %*% y[[i]] for each i. Can anyone please help me? Regards, Jorge Ivan Velez wrote: > > Hi megh, > Perhaps? > > # Data > x = vector("list") > for (i in 1:5) x[[i]] = rnorm(2) > > # 2x2 matrices > res <- lapply(x, function(a) a %*% t(a) ) > res > > # Funcion from ?Reduce > add <- function(x) Reduce("+", x) > > # Summing up! > add(res) > > See ?lapply and ?Reduce for more information. > > HTH, > > Jorge > > > On Wed, Jul 22, 2009 at 3:18 PM, megh <megh700...@yahoo.com> wrote: > >> >> Hi, >> I have created a list object like that : >> x = vector("list") >> for (i in 1:5) x[[i]] = rnorm(2) >> x >> >> Now I want to do two things : >> 1. for each i, I want to do following matrix calculation : t(x[[i]]) %*% >> x[[i]] i.e. for each i, I want to get a 2x2 matrix >> 2. Next I want to get x[[1]] + x[[2]] +.... >> >> I did following : res=vector("list"); res = sapply(x, function(i) >> t(x[[i]]) >> %*% x[[i]]) >> However above syntax is not giving desired result. Any suggestion please? >> >> -- >> View this message in context: >> http://www.nabble.com/A-question-on-operation-on-list-tp24612796p24612796.html >> Sent from the R help mailing list archive at Nabble.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. >> > > [[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. > > -- View this message in context: http://www.nabble.com/A-question-on-operation-on-list-tp24612796p24614641.html Sent from the R help mailing list archive at Nabble.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.