Split a vector of strings over a character to return a matrix

Question

I have

rownames(results.summary)
[1] "2 - 1" "3 - 1" "4 - 1"

What I want is to return a matrix of

2  1
3  1
4  1

The way Ive done it as:

for(i in 1:length(rownames(results.summary)){
  current.split <- unlist(strsplit(rownames(results.summary)[i], "-"))
  matrix.results$comparison.group[i] <- trim(current.split[1])
  matrix.results$control.group[i] <- trim(current.split[2])
}

The trim function basically removes any whitespace on either end.

I've been learning regex and was wondering if there's perhaps a more elegant vectorized solution?

Answer 1

No need to use strsplit, just read it using read.table:

 read.table(text=vec,sep='-',strip.white = TRUE) ## see @flodel comment
  V1 V2
1  2  1
2  3  1
3  4  1

where vec is :

vec <-  c("2 - 1", "3 - 1", "4 - 1")

Answer 2

This should work:

vv <- c("2 - 1", "3 - 1", "4 - 1")
matrix(as.numeric(unlist(strsplit(vv, " - "))), ncol = 2, byrow = TRUE)
#      [,1] [,2]
# [1,]    2    1
# [2,]    3    1
# [3,]    4    1