Deleting multiple columns in R

Question

I have a dataframe df with column names from m1 to m100

I want to delete columns in the range m50 to m100. Is there a faster way to do it than hardcoding it

Answer 1

Assuming you have something like:

mydf <- data.frame(matrix(1:100, ncol = 100, 
                          dimnames = list(NULL, paste0("m", 1:100))))

Simply do:

mydf[paste0("m", 50:100)] <- list(NULL)  ## This is pretty destructive ;-)

---

By the way, you can also do:

subset(mydf, select = m1:m49)

or

subset(mydf, select = -(m50:m100))