CODEWITHSUNDEEP
rfunction
schow
schow

Reputation: 27

function to replace different text strings in r

I am trying to write a function that replaces text with another

regionChange <- function(x){
x <- sub("vic", "161", x, ignore.case = TRUE) 
x <- sub("sa", "159", x, ignore.case = TRUE)
}

test <- c("vic", "sa")
regionChange(test)
test

I don't know why this function doesn't work to produce

[1] "161" "159" instead of

[1] "vic" "sa"

Do I need to write an ifelse statement? I would like to add further substitutions later on and an ifelse statement will get messy.

Upvotes: 0

Views: 43

Answers (2)

talat
talat

Reputation: 70256

The result is returned invisibly because inside your function, the last function call is an assignment. If you want your function to print the result on exit, you can either tell it explicitly, like so:

> print(regionChange(test))
[1] "161" "159"

or you can change your function to one of the following:

regionChange <- function(x){
  x <- sub("vic", "161", x, ignore.case = TRUE) 
  x <- sub("sa", "159", x, ignore.case = TRUE)
  x
}

or 

regionChange <- function(x){
  x <- sub("vic", "161", x, ignore.case = TRUE) 
  sub("sa", "159", x, ignore.case = TRUE)
}

or

regionChange <- function(x){
  x <- sub("vic", "161", x, ignore.case = TRUE) 
  x <- sub("sa", "159", x, ignore.case = TRUE)
  return(x)
}

Note that, in any case (including your existing function definition), your function would properly assign its results to a vector when using

result <- regionChange(test)

Upvotes: 2

CClaire
CClaire

Reputation: 453

It's because you don't return X

regionChange <- function(x){
  x <- sub("vic", "161", x, ignore.case = TRUE) 
  x <- sub("sa", "159", x, ignore.case = TRUE)
return(x)}

test <- c("vic", "sa")
test <- regionChange(test)
test

Upvotes: 2

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