Question

I’m writing my first function ever (including any other programming language) and I’m a little confused on the proper structure for if, else and ifelse. I’ve searched a ton of examples, but none are that clear to me.

Situation – I’m trying to bucket clients by how long they have been clients for, then turn that into a factor.

#Sample Data
clientID <- round(runif(2,min=2000, max=3000),0)
MonthsSinceSignUp <- round(runif(20,min=1, max=60),0)
df <- data.frame(cbind(clientID,MonthsSinceSignUp))

For a given client, I would like to determine if they have been so for less than a year, more than year, but less than 2, etc.

This is my first crack at a function:

ClientAgeRange <- function(MonthsSinceSignUp) {
  if (MonthsSinceSignUp < 13) {ClientAgeRange <- '1 year'}
} else {
  if (MonthsSinceSignUp > 13 & MonthsSinceSignUps < 25) {ClientAgeRange <- '2 years'}
} else {ClientAgeRage <- '3+ years'}

The error that I keep getting is:
Error: unexpected '}' in "}", which would indicate I’m missing or have an extra closing bracket. However, despite my trouble shooting, I can’t locate it. But – I think in general, I’m not apply the correct structure to the function. I’m trying to produce a if this, then set this variable as that. How can I structure this function properly?

Lastly – if I wanted to add the output of the function to the dataframe, is apply the correct way to do so?

Answer 1

An answer in two parts:

1. A tip
2. A fix

The tip:

My first tip is to use a code editor that does bracket matching. For example, in Notepad++ you get this:

PS. I’m not recommending Notepad++ – use Rstudio instead – I’m simply using Notepad++ because of the garish (and thus easy to spot) colours

Notice that the highlighted brace (in red) matches with a brace in the middle of your function. This reveals that there is redundant brace at the end of your first if. So, fix that first:

OK, now there is no matching brace (no highlighted red), so you need to add the missing brace at the end of your function:

---

The fix:

But you can vastly simplify your function if you use cut, which is designed to do this type of analysis:

ClientAgeRange <- function(x) {
  cut(x, breaks=c(0, 13, 25, Inf), labels=c("1 year", "2 years", "3+ years"))
}

Try it on your code:

ClientAgeRange(df$MonthsSinceSignUp)
 [1] 2 years  1 year   3+ years 2 years  3+ years 3+ years 2 years  2 years  3+ years 3+ years 1 year  
[12] 3+ years 2 years  3+ years 3+ years 3+ years 3+ years 3+ years 3+ years 3+ years
Levels: 1 year 2 years 3+ years