R: Removing multiple columns from data frame based on vector values

Question

I have a data frame dataGL_all:

Date<-c("01-01-15 04:00","01-01-15 04:20","01-01-15 04:40")
FLIin<-c(96,39,72)
FLIout<-c(173,147,103)
FBEin<-c(96,116,166)
FBEout<-c(32,53,120)
dataGL_all<-data.frame(Date, FLIin, FLIout, FBEin, FBEout)

Furthermore, I have a vector:

Remove <- c("FBEin", "FLIout")

I would a piece of code that removes the columns in the vector Remove from the data frame dataGL_all. I have tried many combinations of functions (eg grep(), c() and names()) but can't get it working ... would appreciate help :) thx

PS My "real" data frame contains 68 columns where of I would like to remove 36 (the ones in the vector).

Answer 1

dataGL_all[, !names(dataGL_all) %in% Remove]

should do the trick. Or, if you want grep :

dataGL_all[, grep(paste(Remove, collapse = "|"), names(dataGL_all), invert = T)]

Answer 2

Just to add some more possibilities, with data.table package these kind of operation are very simple. You can either temporarily remove columns using ! and with = FALSE combination. Or you can modify your data set by reference while evaluating this vector using () within data.table environment and assigning NULL to it using := assignment operator, so here goes:

Load the package and convert to a data.table class

library(data.table)
setDT(dataGL_all)

Then either do

dataGL_all[, !Remove, with = FALSE]
#              Date FLIin FBEout
# 1: 01-01-15 04:00    96     32
# 2: 01-01-15 04:20    39     53
# 3: 01-01-15 04:40    72    120

Or update the data set by reference

dataGL_all[, (Remove) := NULL][]
#              Date FLIin FBEout
# 1: 01-01-15 04:00    96     32
# 2: 01-01-15 04:20    39     53
# 3: 01-01-15 04:40    72    120