How do I combine levels within a variable in R

Question

My variable "Satisfaction" has levels 1, 2, 3, 4.

I want to combine 3,4 to create a new level: "0"; and 1,2 to create new level: "1"

I have done this:

combineLevels(EB734_May_2010$Satisfaction, levs = c("3","4"), newLabel =("0"))

After running the above code, I ran the levels function again, but still got 1,2,3,4. Is there anything I'm doing wrong?

Thanks

score 2 · Answer 1 · answered Aug 31 '20 at 10:01

2

forcats::fct_recode(
  EB734_May_2010$Satisfaction, 
  "0" = "3", "0" = "4", "1" = "1", "1" = "2"
)

answered Aug 31 '20 at 10:01

det

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`forcats` is nice library for factors in R (it's also anagram for factors) – det Aug 31 '20 at 10:05

Darren Tsai · Answer 2 · 2020-08-31T10:22:48.533

By a base solution, you can assign a named list to the levels of a factor object.

x <- factor(rep(1:4, each = 2))

# [1] 1 1 2 2 3 3 4 4
# Levels: 1 2 3 4

levels(x) <- list("0" = c(3, 4), "1" = c(1, 2))
x

# [1] 1 1 1 1 0 0 0 0
# Levels: 0 1

Or using recode() from dplyr:

dplyr::recode(x, "1" = "1", "2" = "1", "3" = "0", "4" = "0")

# [1] 1 1 1 1 0 0 0 0
# Levels: 1 0

It can also use a named character vector to recode factors with unquote splicing.

dplyr::recode_factor(x, !!!setNames(c(1, 1, 0, 0), levels(x)))

# [1] 1 1 1 1 0 0 0 0
# Levels: 1 0

How do I combine levels within a variable in R

2 Answers2