Sorry, the above should have been > mymean <- function(x) Reduce("+", x)/length(x) > mymean(b) [,1] [,2] [1,] 10.33333 12.33333 [2,] 11.33333 13.33333
Apologies for the noise. Best, Jorge On Thu, Mar 24, 2011 at 3:54 PM, Jorge Ivan Velez <> wrote: > Hi Hui, > > Ssee ?Reduce for more details. You might try something along the lines of > > > mymean <- function(x) Reduce("+", x)/length(x) > > add(b) > [,1] [,2] > [1,] 10.33333 12.33333 > [2,] 11.33333 13.33333 > > HTH, > Jorge > > > On Thu, Mar 24, 2011 at 11:07 AM, Hui Du <> wrote: > >> Hi All, >> >> Suppose I have data like >> >> b[[1]] = matrix(1:4, 2, 2) >> b[[2]] = matrix(10:13, 2, 2) >> b[[3]] = matrix(20:23, 2, 2) >> >> [[1]] >> [,1] [,2] >> [1,] 1 3 >> [2,] 2 4 >> >> [[2]] >> [,1] [,2] >> [1,] 10 12 >> [2,] 11 13 >> >> [[3]] >> [,1] [,2] >> [1,] 20 22 >> [2,] 21 23 >> >> Now I want to calculate the mean of each cell across the >> list. For example mean of (b[[1]][1,1], b[[2]][1,1], b[[3]][1,1]), mean of >> (b[[1]][1,2], b[[2]][1,2], b[[3]][1,2]) etc. e.g. mean of (1, 10, 20), mean >> of(3, 12, 22). Could somebody tell me how to do it? Thank you in advance. >> >> HXD >> >> [[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.