if_else() is a vectorized if-else. Compared to the base R equivalent,
ifelse(), this function allows you to handle missing values in the
condition with missing and always takes true, false, and missing
into account when determining what the output type should be.
if_else(condition, true, false, missing = NULL, ..., ptype = NULL, size = NULL)A logical vector
Vectors to use for TRUE and FALSE values of
condition.
Both true and false will be recycled
to the size of condition.
true, false, and missing (if used) will be cast to their common type.
If not NULL, will be used as the value for NA values of
condition. Follows the same size and type rules as true and false.
These dots are for future extensions and must be empty.
An optional prototype declaring the desired output type. If
supplied, this overrides the common type of true, false, and missing.
An optional size declaring the desired output size. If supplied,
this overrides the size of condition.
A vector with the same size as condition and the same type as the common
type of true, false, and missing.
Where condition is TRUE, the matching values from true, where it is
FALSE, the matching values from false, and where it is NA, the matching
values from missing, if provided, otherwise a missing value will be used.
x <- c(-5:5, NA)
if_else(x < 0, NA, x)
#> [1] NA NA NA NA NA 0 1 2 3 4 5 NA
# Explicitly handle `NA` values in the `condition` with `missing`
if_else(x < 0, "negative", "positive", missing = "missing")
#> [1] "negative" "negative" "negative" "negative" "negative" "positive"
#> [7] "positive" "positive" "positive" "positive" "positive" "missing"
# Unlike `ifelse()`, `if_else()` preserves types
x <- factor(sample(letters[1:5], 10, replace = TRUE))
ifelse(x %in% c("a", "b", "c"), x, NA)
#> [1] 1 NA NA 2 NA 2 NA NA 2 2
if_else(x %in% c("a", "b", "c"), x, NA)
#> [1] a <NA> <NA> b <NA> b <NA> <NA> b b
#> Levels: a b d e
# `if_else()` is often useful for creating new columns inside of `mutate()`
starwars %>%
mutate(category = if_else(height < 100, "short", "tall"), .keep = "used")
#> # A tibble: 87 × 2
#> height category
#> <int> <chr>
#> 1 172 tall
#> 2 167 tall
#> 3 96 short
#> 4 202 tall
#> 5 150 tall
#> 6 178 tall
#> 7 165 tall
#> 8 97 short
#> 9 183 tall
#> 10 182 tall
#> # ℹ 77 more rows