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Vectorised if else.

Source: R/if-else2.R
if_else2.Rd

Vectorised if else that if true returns first possibility otherwise returns second possibility (even if the condition is a missing value). When searching character vectors an alternative solution is to use str_detect2().

Usage

if_else2(condition, true, false, error = FALSE)

Arguments

condition

A logical vector

true, false

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.

error

A logical value. If TRUE, provides an informative error message if no matches are found.

Value

Where condition is TRUE, the matching value from true, where it's FALSE or NA, the matching value from false.

See also

ifelse() and dplyr::if_else().

Examples

# consider the following data frame
data <- tibble::tibble(
  x = c(TRUE, FALSE, NA),
  y = c("x is false", NA, "hello")
)

# with a single vector if_else2() behaves the same as the default call to if_else().
dplyr::mutate(data,
  y1 = dplyr::if_else(y != "x is false", "x is true", y),
  y2 = if_else2(y != "x is false", "x is true", y)
)
#> # A tibble: 3 × 4
#>   x     y          y1         y2        
#>   <lgl> <chr>      <chr>      <chr>     
#> 1 TRUE  x is false x is false x is false
#> 2 FALSE NA         NA         NA        
#> 3 NA    hello      x is true  x is true 

# however in the case of a second vector the use of
# if_else2() does not introduce missing values
dplyr::mutate(data,
  x1 = dplyr::if_else(stringr::str_detect(y, "x is false"), FALSE, x),
  x2 = if_else2(stringr::str_detect(y, "x is false"), FALSE, x)
)
#> # A tibble: 3 × 4
#>   x     y          x1    x2   
#>   <lgl> <chr>      <lgl> <lgl>
#> 1 TRUE  x is false FALSE FALSE
#> 2 FALSE NA         NA    FALSE
#> 3 NA    hello      NA    NA   

# in the case of regular expression matching an alternative is to use
# str_detect2()
dplyr::mutate(data,
  x3 = dplyr::if_else(str_detect2(y, "x is false"), FALSE, x)
)
#> # A tibble: 3 × 3
#>   x     y          x3   
#>   <lgl> <chr>      <lgl>
#> 1 TRUE  x is false FALSE
#> 2 FALSE NA         FALSE
#> 3 NA    hello      NA