How to convert factor levels to list, in R

Question

Imagine a data frame such as df1 below:

df1 <- data.frame(v1 = as.factor(c("m0p1", "m5p30", "m11p20", "m59p60", "m59p60")))

How do I create a list of all the levels of a variable? Thank you.

`levels(df1$v1)` will give you a character vector of levels. — scoa, May 09 '15 at 13:09
Related: http://stackoverflow.com/questions/5869539/confusion-between-factor-levels-and-factor-labels — zx8754, May 09 '15 at 15:16

score 18 · Accepted Answer · answered May 09 '15 at 13:31

18

To print the levels in the variable, use levels() as @scoa says:

levels(df1$v1)

To make it an explicit list use as.list() as well:

l <- as.list(levels(df1$v1))
l

answered May 09 '15 at 13:31

Phil

score 4 · Answer 2 · edited Feb 02 '18 at 05:19

4

This converts the factor to something manageable:

df1$v1 <- vapply(df1$v1, paste, collapse = ", ", character(1L))

edited Feb 02 '18 at 05:19

Sunil

answered Feb 02 '18 at 05:05

Shashank Raina

you can do the same more simply with `as.caracter(df1$v1)' – Marco Stamazza Aug 04 '20 at 01:30

2 Answers2