Enter new column names as string in dplyr's rename function

Question

dplyr\'s rename functions require the new column name to be passed in as unquoted variable names. However I have a function where the column name is constructed by pasting a

Answer 1

I think this is what you were looking for. It is the use of rename_ as @Henrik suggested, but the argument has an, lets say, interesting, name:

> myFunc <- function(df, col){
+   new <- paste0(col, '_1')
+   out <- dplyr::rename_(df, .dots=setNames(list(col), new))
+   return(out)
+ }
> myFunc(data.frame(x=c(1,2,3)), "x")
  x_1
1   1
2   2
3   3
>

Note the use of setNames to use the value of new as name in the list.

Answer 2

Recent updates to tidyr and dplyr allow you to use the rename_with function.

Say you have a data frame:

library(tidyverse)

df <- tibble(V0 = runif(10), V1 = runif(10), V2 = runif(10), key=letters[1:10])

And you want to change all of the "V" columns. Usually, my reference for columns like this comes from a json file, which in R is a labeled list. e.g.,

colmapping <- c("newcol1", "newcol2", "newcol3")
names(colmapping) <- paste0("V",0:2)

You can then use the following to change the names of df to the strings in the colmapping list:

df <- rename_with(.data = df, .cols = starts_with("V"), .fn = function(x){colmapping[x]})