Try this: apply(array(unlist(mymats), dim = c(dim(mymats[[1]]), length(mymats))), 1:2, mode)
The error was in c(length(mymats), dim(mymats[[1]])) On Tue, Sep 21, 2010 at 3:19 PM, Gregory Ryslik <rsa...@comcast.net> wrote: > Ack, apologies for the previous email. What I meant to say is that the > first element is calculated incorrectly (1,1) should be 2, instead it is 3. > I've been staring at the code for two long. I've copied it in again for > convenience. > > mymats <- vector('list', 4) > set.seed(246) > > # Generate a list of 4 3 x 3 matrices > for(i in 1:4) mymats[[i]] <- matrix(sample(1:9), nrow = 3) > > mymats[[1]][1,1]<-3 > mymats[[1]][1,2]<-3 > mymats[[1]][1,3]<-1 > mymats[[2]][2,1]<-2 > mymats[[1]][2,2]<-3 > mymats[[1]][2,3]<-1 > mymats[[1]][3,1]<-2 > mymats[[1]][3,2]<-2 > mymats[[1]][3,3]<-3 > > mymats[[2]][1,1]<-2 > mymats[[2]][1,2]<-3 > mymats[[2]][1,3]<-2 > mymats[[2]][2,1]<-1 > mymats[[2]][2,2]<-2 > mymats[[2]][2,3]<-2 > mymats[[2]][3,1]<-1 > mymats[[2]][3,2]<-3 > mymats[[2]][3,3]<-2 > > mymats[[3]][1,1]<-NA > mymats[[3]][1,2]<-2 > mymats[[3]][1,3]<-2 > mymats[[3]][2,1]<-2 > mymats[[3]][2,2]<-3 > mymats[[3]][2,3]<-1 > mymats[[3]][3,1]<-2 > mymats[[3]][3,2]<-2 > mymats[[3]][3,3]<-3 > > mymats[[4]][1,1]<-2 > mymats[[4]][1,2]<-1 > mymats[[4]][1,3]<-2 > mymats[[4]][2,1]<-3 > mymats[[4]][2,2]<-2 > mymats[[4]][2,3]<-3 > mymats[[4]][3,1]<-1 > mymats[[4]][3,2]<-2 > mymats[[4]][3,3]<-1 > > mymats > > > mode <- function(x){ > as.numeric(names(which.max(table(x)))) > } > apply(array(unlist(mymats), dim = c(length(mymats), dim(mymats[[1]]))), 1: > 2, mode) > > > On Sep 21, 2010, at 10:08 AM, Henrique Dallazuanna wrote: > > Try this: > > mode <- function(x, ...) > as.numeric(names(which.max(table(x)))) > apply(array(unlist(mymats), dim = c(length(mymats), dim(mymats[[1]]))), > 1:2, mode) > > > On Tue, Sep 21, 2010 at 10:47 AM, Gregory Ryslik <rsa...@comcast.net>wrote: > >> Hi Everyone, >> >> I am interested in taking the mode over several thousand matrices. I show >> an example below. For the [1,1] entry of my "mode" matrix that I want to >> create I would like to have a "2". For the [1,2] entry I would want a 2. >> For the [2,2] entry it would be 4 and so forth. Earlier, I was working with >> continuous cases and thus each (n,m) element was simply an average. I was >> able to then do element-wise addition and counting using the "Reduce" >> function and then the average would be totalsum/totalcount where the NA >> terms were discounted. Here, it's not exactly a binary case so Reduce >> doesn't quite work as well. I'm open to suggestions but would as always like >> to avoid long loops as that will significantly bump up running time over >> several thousand trees. Similarly, I would not like to do a lot of sorts to >> find the mode either... >> >> Thanks for your help! >> >> mymats >> [[1]] >> [,1] [,2] [,3] >> [1,] 0 2 1 >> [2,] 2 3 3 >> [3,] 2 1 2 >> >> [[2]] >> [,1] [,2] [,3] >> [1,] 1 2 4 >> [2,] 2 4 4 >> [3,] 3 4 5 >> >> [[3]] >> [,1] [,2] [,3] >> [1,] 2 3 1 >> [2,] 3 4 2 >> [3,] 5 1 3 >> >> [[4]] >> [,1] [,2] [,3] >> [1,] 2 4 2 >> [2,] 1 NA 2 >> [3,] 2 3 1 >> >> [[5]] >> [,1] [,2] [,3] >> [1,] NA 2 1 >> [2,] 2 4 1 >> [3,] 1 3 2 >> ______________________________________________ >> 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. >> > > > > -- > Henrique Dallazuanna > Curitiba-Paraná-Brasil > 25° 25' 40" S 49° 16' 22" O > > > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[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.