How to drop columns by name in a data frame?

Question

I have a large data set and I would like to read specific columns or drop all the others. data <- read.dta("file.dta")I select the columns that I'm not interested in: var.out <- names(data)[!names(data) %in% c("iden", "name", "x_serv", "m_serv")]and than I'd like to do something like: for(i in 1:length(var.out)) { paste("data$", var.out[i], sep="") <- NULL }to drop all the unwanted columns. Is this the optimal solution?

Answer 1

There are multiple ways to achieve this without looping over the data.

I would use package dplyr in tidyverse and use select function, but if you want to use base R, this is my suggestion:

data[,!names(data) %in% c("iden", "name", "x_serv", "m_serv")]

Simply using this would drop out columns c("iden", "name", "x_serv", "m_serv").