[R] how to create column names for the matrix

[ruipbarradas at sapo.pt]

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]]
>
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