Skip to content

Instantly share code, notes, and snippets.

@romainx

romainx/lump.R

Last active Apr 19, 2020
Embed
What would you like to do?
[Reduce number of categories] Reduce the number of categories by lumping some of them together into an "Other" category #R
# Refs: https://forcats.tidyverse.org/reference/fct_lump.html
# A test data frame
set.seed(2)
df <- tibble(cat = factor(sample(c("a", "b", "c", "d"), 10, replace = TRUE)),
val = sample(1:10))
df %>% head()
# A tibble: 6 x 2
# cat val
# <fct> <int>
# 1 a 9
# 2 c 2
# 3 b 3
# 4 b 1
# 5 d 8
# 6 d 10
# Lumping by number of values -----
# Count the number of values by categories
df %>%
count(cat)
# A tibble: 4 x 2
# cat n
# <fct> <int>
# 1 a 4
# 2 b 2
# 3 c 1
# 4 d 3
# Keep only the 2 most frequent categories, lumping together the remaining
# categories in the "Other" category
df %>%
group_by(cat = forcats::fct_lump_n(cat, 2)) %>%
count(cat)
# A tibble: 3 x 2
# Groups: cat [3]
# cat n
# <fct> <int>
# 1 a 4
# 2 d 3
# 3 Other 3
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.