How to turn a string column into numeric and save string values as labels not to lose information in R?

I would like to convert a string column into numeric to facilitate calculation, but I would also like to preserve the information of the values. Thus, I would like to assign the string values as labels. Not sure if people do this in R, but it was common practice in Stata, so whenever you pulled a table or plotted a graph you could see the labels instead of assigned numbers. The problem that I have is that there are more than 20 string values, and more than 10k rows. So, let’s say I have the following dataframe:

df <- data.frame(color = c("green", "green", "blue", "red", "green", "blue", "red"))
df
  color
1 green
2 green
3  blue
4   red
5 green
6  blue
7   red

How can I assign one number for each color, save the string information, and assign it as value labels?

>Solution :

You might want to take a look at this

I am afraid you cannot have duplicate row names in a data.frame in R. You might want to use a factor instead if you have repeated strings. The next example produces a bar plot with the labels using this approach.

library(tidyverse)

df |> 
  mutate(color = factor(color)) |> 
  ggplot(aes(x = color)) +
  geom_bar()