[R] how to create column names for the matrix

[lily li]

Thanks, this works. I thought the code should put in the for loop, but it
turns out an extra line.

On Wed, Jul 27, 2016 at 12:50 PM, <ruipbarradas at sapo.pt> wrote:

> Hello,
>
> Try
>
>
> chars = c('A','B','C','D')
> matrix1 = matrix(nrow = length(1:100), ncol = length(1:5)*length(chars))
> k = 0
> for(i in 1:length(1:5)){  # or more simply just for(i in 1:5)
>   for(j in 1:length(chars)){
>     k = k+1
>     matrix1[,k] = k
>   }
> }
> matrix1
> tmp <- expand.grid(chars, 1:5, stringsAsFactors = FALSE)
> nms <- paste(tmp[[2]], tmp[[1]], sep = "-")
> rm(tmp)
> colnames(matrix1) <- nms
>
> head(matrix1)
>
>
> Hope this helps,
>
> Rui Barradas
>
>
> Citando lily li <chocold12 at gmail.com>:
>
> Hi all,
>
> I want to ask that how to create column names for a matrix. For example,
> the matrix below, the column names should be: 1-A, 1-B, 1-C, 1-D, 2-A, 2-B,
> 2-C, 2-D, 3-A, etc. Thanks for your help.
>
> chars = c('A','B','C','D')
> matrix1 = matrix(nrow = length(1:100), ncol = length(1:5)*length(chars))
> k = 0
> for(i in seq(1:length(1:5))){
> for(j in seq(1:length(chars))){
>    k = k+1
>    matrix1[,k] = c(1:100)[k]
> }
> }
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.htmland provide commented,
> minimal, self-contained, reproducible code.
>
>
>
>

	[[alternative HTML version deleted]]