Change selected elements of character vector

Question

Is there a shorter version for the folowing principle to rename certain columns of a data frame?

data1<-data.frame(\"a\"=1:3,\"b\"=1:3,\"c\"=1:3)

data1Names&         


        

Answer 1

Use match to replace selected elements and to respect the order when using names<-...

names(data1)[ match( c("a", "c") , names(data1) ) ] <- c("hello", "world")
#  hello b world
#1     1 1     1
#2     2 2     2
#3     3 3     3

Swapping the desired order of renaming...

names(data1)[ match( c("c", "a") , names(data1) ) ] <- c("hello", "world")
#  world b hello
#1     1 1     1
#2     2 2     2
#3     3 3     3

Answer 2

The data.table package has a setnames function that will work on data.frames

library(data.table)
data1<-data.frame("a"=1:3,"b"=1:3,"c"=1:3)
#setnames(data1, "a", "hello")
#setnames(data1, "c", "world")
# or in one step
setnames(data1, c("a", "c"), c("hello", "world"))
data1
#  hello b world
#1     1 1     1
#2     2 2     2
#3     3 3     3

All of the answers so far will make a copy of the data.frame. setnames has the added benefit that it changes the names by reference, without making a copy of the data.frame.

Answer 3

setNames can be helpful

> setNames(data1, c("hello", "b", "world"))
  hello b world
1     1 1     1
2     2 2     2
3     3 3     3

another alternative

> names(data1)[names(data1) %in% c("a", "c")] <- c("hello", "world")
> data1
  hello b world
1     1 1     1
2     2 2     2
3     3 3     3

Answer 4

You can use rename from the plyr package:

data1<-data.frame("a"=1:3,"b"=1:3,"c"=1:3)
> rename(data1,c('a' = 'hello','b' = 'world'))
  hello world c
1     1     1 1
2     2     2 2
3     3     3 3