Recoding

Last updated: January 18, 2021

Basic recoding

df <- df %>%
  mutate(
    smoke = recode(
      smoke,
      "1" = "Yes",
      "0" = "No"
    )
  )

This will recode 1 to Yes, and 0 to No. A few notes:

• If the original values are numeric, you still have to put them in quotes in recode().
• You will get a warning if your recoding is not exhaustive. To suppress, add .default = NONE to recode().

Recoding logical values (TRUE and FALSE)

recode() currently does not work with logical values:

recode(c(T,F), T=1, F=2)
# Error in UseMethod("recode") : 
#  no applicable method for 'recode' applied to an object of class "logical"

To make this work, do the following:

recode(as.numeric(c(T,F)), "1"=1, "0"=2)
# [1] 1 2

Setup for running the example code

This example uses the birthwt dataset. If you want to run the example code, first run this:

library(MASS) # Needed for `birthwt` dataset
library(tidyverse)
df <- birthwt # Information: https://stat.ethz.ch/R-manual/R-devel/library/MASS/html/birthwt.html

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