refer to range of columns by name in R

Question

I need help with something that might be fairly simple in R. I want to refer to a range of columns in a data frame (e.g., extracting a few select variables). However, I don\

Answer 1

Getting a range of columns can be done in several ways. subset(data.frame, select = name4:name10), works but is quite long. I used that before I got annoyed writing long commands for a simple thing. I made a function to tackle the naming columns / not remembering column numbers in large data frames:

coln <- function(X){
  y <- rbind(seq(1,ncol(X)))
  colnames(y) <- colnames(X)
rownames(y) <- "col.number"
  return(y)} 

Here is how it works:

df <- data.frame(a = 1:10, b =10:1, c = 1:10)
coln(df)
           a b c
col.number 1 2 3

Now you can call them with numbers and still look at names.