使用R的标题名称查找和排除具有某些模式的数据框列

Question

I'm trying to find a solution to a data frame subsetting need I have.

I have a data frame that with the following general structure I have named wrkDat

A    R2_A    B    R2_B    .....    Z    R2_Z
1.1  0.99    2.2  0.97    .....    26.6 0.96
1.9  0.89    4.2  0.99    .....    12.8 0.78

I would like to be able to selectively subset so I don't have the R2 columns. Initially I was thinking something like the following would work, but it does not.

selected <- "^R2." %in% colnames(wrkDat)
wrkDat <- wrkDat[,!selected]

Answer 1

Thank you to Mitra and plafort for getting me thinking about the grep functions. I found the following that worked perfectly. I don't know what I was thinking trying to use regex patterns with %in%....

selected <- grepl("^R2.", colnames(wrkDat))
wrkDat <- wrkDat[,!selected]

Answer 2

wrkDat <- wrkDat[,-grep("^R2.",colnames(wrkDat)]

应该可以

Answer 3

You could do:

library(dplyr)
df %>% select(-starts_with("R2"))