Replace range of values in a column with a factor using dplyr-CodePudding

I have a question similar to this, but instead of two factors, I would like to create four factors. Replace range of values for factor with levels

How do I do that? I don't know how to share my own data table so I will use the iris dataset.

library(datasets)
data(iris)

Let's say I want to categorize Sepal.Length into 4 categories 4.3-4.9,5-6,6.1-7,7.1-7.9 and label each range as A,B,C,D (factors) in a new column. Can this be done using the dplyr package? I came across several similar questions that use the "cut" function but I was not able to use it without getting an error message.

CodePudding user response：

You can use cut inside mutate. Pass Sepal.Length as the first argument, the vector of cut points you want to use for the breaks argument (it should be length-5), and the labels you want to assign via the labels argument.

library(tidyverse)

iris %>%
  as_tibble() %>%
  mutate(newcol = cut(Sepal.Length, breaks = c(0, 1.9, 3.9, 5.9, 8), 
                      labels = LETTERS[1:4]))
#> # A tibble: 150 x 6
#>    Sepal.Length Sepal.Width Petal.Length Petal.Width Species newcol
#>           <dbl>       <dbl>        <dbl>       <dbl> <fct>   <fct> 
#>  1          5.1         3.5          1.4         0.2 setosa  C     
#>  2          4.9         3            1.4         0.2 setosa  C     
#>  3          4.7         3.2          1.3         0.2 setosa  C     
#>  4          4.6         3.1          1.5         0.2 setosa  C     
#>  5          5           3.6          1.4         0.2 setosa  C     
#>  6          5.4         3.9          1.7         0.4 setosa  C     
#>  7          4.6         3.4          1.4         0.3 setosa  C     
#>  8          5           3.4          1.5         0.2 setosa  C     
#>  9          4.4         2.9          1.4         0.2 setosa  C     
#> 10          4.9         3.1          1.5         0.1 setosa  C     
#> # ... with 140 more rows

^{Created on 2023-01-30 with reprex v2.0.2}