Fast if else

iif is a faster and more robust replacement of ifelse. It is comparable to dplyr::if_else, hutils::if_else and data.table::fifelse. It returns a value with the same length as test filled with corresponding values from yes, no or eventually na, depending on test. It does not support S4 classes.

Usage

iif(test, yes, no, na=NULL, tprom=FALSE, nThread=getOption("kit.nThread"))

Arguments

test: A logical vector.
yes, no: Values to return depending on TRUE/FALSE element of test. They must be the same type and be either length 1 or the same length of test.
na: Value to return if an element of test is missing. It must be the same type as yes/no and be either length 1 or the same length of test. Please note that NA is treated as logical value of length 1 as per the R documentation. NA_integer_, NA_real_, NA_complex_ and NA_character_ are equivalent to NA but for integer, double, complex and character. Default value for argument na is NULL and will automatically default to the equivalent NA type of argument yes.
tprom: Argument to indicate whether type promotion of yes and no is allowed or not. Either FALSE or TRUE, default is FALSE to not allow type promotion.
nThread: A integer for the number of threads to use with openmp. Default value is getOption("kit.nThread").

Details

In contrast to ifelse attributes are copied from yes to the output. This is useful when returning Date, factor or other classes. Like dplyr::if_else and hutils::if_else, the na argument is by default set to NULL. This argument is set to NA in data.table::fifelse. Similarly to dplyr::if_else and when tprom=FALSE, iif requires same type for arguments yes and no. This is not strictly the case for data.table::fifelse which will coerce integer to double. When tprom=TRUE, iif behavior is similar to base::ifelse in the sense that it will promote or coerce yes and noto the "highest" used type. Note, however, that unlike base::ifelse attributes are still conserved.

Value

A vector of the same length as test and attributes as yes. Data values are taken from the values of yes and no, eventually na.

Author

Morgan Jacob

Examples

x = c(1:4, 3:2, 1:4)
iif(x > 2L, x, x - 1L)
#>  [1] 0 1 3 4 3 1 0 1 3 4

# unlike ifelse, iif preserves attributes, taken from the 'yes' argument
dates = as.Date(c("2011-01-01","2011-01-02","2011-01-03","2011-01-04","2011-01-05"))
ifelse(dates == "2011-01-01", dates - 1, dates)
#> [1] 14974 14976 14977 14978 14979
iif(dates == "2011-01-01", dates - 1, dates)
#> [1] "2010-12-31" "2011-01-02" "2011-01-03" "2011-01-04" "2011-01-05"
yes = factor(c("a","b","c"))
no = yes[1L]
ifelse(c(TRUE,FALSE,TRUE), yes, no)
#> [1] 1 1 3
iif(c(TRUE,FALSE,TRUE), yes, no)
#> [1] a a c
#> Levels: a b c

# Example of using the 'na' argument
iif(test = c(-5L:5L < 0L, NA), yes = 1L, no = 0L, na = 2L)
#>  [1] 1 1 1 1 1 0 0 0 0 0 0 2

# Example of using the 'tprom' argument
iif(test = c(-5L:5L < 0L, NA), yes = 1L, no = "0", na = 2L, tprom = TRUE)
#>  [1] "1" "1" "1" "1" "1" "0" "0" "0" "0" "0" "0" "2"