Combine levels from two or more factors to create a new factor

Computes a factor whose levels are all the combinations of the levels of the input factors.

fct_cross(.f, ..., sep = ":", keep_empty = FALSE)

Arguments

.f	A factor or character vector
...	Additional factors or character vectors
sep	A character string to separate the levels
keep_empty	If TRUE, keep combinations with no observations as levels

Value

The new factor

Examples

fruit <- factor(c("apple", "kiwi", "apple", "apple"))
colour <- factor(c("green", "green", "red", "green"))
eaten <- c("yes", "no", "yes", "no")
fct_cross(fruit, colour)
#> [1] apple:green kiwi:green  apple:red   apple:green
#> Levels: apple:green apple:red kiwi:green
fct_cross(fruit, colour, eaten)
#> [1] apple:green:yes kiwi:green:no   apple:red:yes   apple:green:no 
#> Levels: apple:green:no apple:green:yes apple:red:yes kiwi:green:no
fct_cross(fruit, colour, keep_empty = TRUE)
#> [1] apple:green kiwi:green  apple:red   apple:green
#> Levels: apple:green kiwi:green apple:red kiwi:red