r - How to trim the column name of the matrix?

Question

I have matirx, it's column names have two part, I just want to keep the first part.

>colnames(mymatrix)

[1] "AF|2312"       "BWDS|54"         "JFD|2111"

so I just want to keep part of colnames before |

How can I implement it in R ?

Answer 1

An alternative method uses strsplit(), a regex short form for 'everything but letters' to split the vector on, and code to keep only the first part: the letters before the pipe (the negative 2).

var  <- c("AF|2312", "BWDS|54", "JFD|2111")

var  <- sapply(strsplit(var, split = "\W"), "[", -2)

var