Recoding values with dpylr using a lookup table

Question

Is there a way to use the recode function of dpylr together with a lookup table (data.frame or list)?

What I would like to have would look something like this:

# Recode values with list of named arguments
data <- sample(c("a", "b", "c", "d"), 10, replace = T) 
lookup <- list(a = "Apple", b = "Pear") 
dplyr::recode(data, lookup)

I found the mapvalues and revalue functions from the plyr package. Combining them is possible as explained here. However, I am wondering whether something similar is possible with dplyr only.

akrun · Answer 1 · 2017-01-08T16:13:25.263

5

We can use base R

v1 <- unlist(lookup)[data]
ifelse(is.na(v1), data, v1)

edited Jan 08 '17 at 16:13

answered Jan 08 '17 at 15:01

akrun

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Not a *dplyr* function, but *base R* is ok too. – Bushroot Jan 08 '17 at 16:43

score 5 · Answer 2 · answered Jan 08 '17 at 16:02

5

do.call(dplyr::recode, c(list(data), lookup))

[1] "Pear" "c"    "d"    "c"    "Pear" "Pear" "d"    "c"    "d"    "c"

answered Jan 08 '17 at 16:02

Axeman

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score 5 · Accepted Answer · answered Dec 01 '20 at 13:36

5

It works like this:

dplyr::recode(data, !!!lookup)

Also useful with mutate in a dataframe tibble:

df <- tibble(code = data)

df %>% 
  mutate(fruit = recode(code, !!!lookup))

answered Dec 01 '20 at 13:36

Martin

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Recoding values with dpylr using a lookup table

3 Answers3