CODEWITHSUNDEEP
rloopsfor-loopif-statement
Александр Суворов
Александр Суворов

Reputation: 11

R loops with factor creation

I want to check if there are less than 4 uniques in my variable, and it's true, I want to create a factor from it.

I created a function:

 checker <- function(x) {
  if (is.numeric(x) == TRUE) {

   if (length(unique(x)) < 5) {
       x <- factor(x)
   }

} else {
  break
}
  return(x)
}

But it still returns numeric vectors.

I suppose, for some reason 

x <- factor(x)

doesn't work, when I tried:

checker <- function(x) {
    x <- factor(x)
    return(x)
}

The cycle returns numeric values

Upvotes: 0

Views: 177

Answers (2)

Ronak Shah
Ronak Shah

Reputation: 389165

You can try this function

checker <- function(x) {
   if (is.numeric(x) & length(unique(x)) < 5)
      factor(x)
   else x
}

and then apply it using lapply

df[] <- lapply(df, checker)
str(df)
#'data.frame':  6 obs. of  2 variables:
# $ a: Factor w/ 4 levels "1","2","3","4": 1 2 3 3 4 3
# $ b: int  1 2 3 4 5 6

Or as @akrun suggests an option with dplyr would be

library(dplyr)
df %>% mutate_if(~ is.numeric(.) && n_distinct(.) < 5, factor)

data

df <- data.frame(a = c(1, 2, 3, 3, 4, 3), b = 1:6)

Upvotes: 1

ThomasIsCoding
ThomasIsCoding

Reputation: 102309

Try the function below:

checker <- function(x) ifelse(length(unique(x))< 5, return(factor(x)), return(x))

Upvotes: 0

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