crosstabs.Rd
xtabs requires two arguments (na.action and exclude) to show missing values along with other values. This function defaults to including missings and has only one argument
crosstabs(x, ..., exclude = NULL)
x | passed to xtabs if it is a formula, transformed into a formula if it's a single object |
---|---|
... | passed to xtabs |
exclude | defaults to NULL (i.e. includes NA) |
x = NA crosstabs(~ x)#> x #> <NA> #> 1