vctrs (version 0.4.2)

partial_factor: Partially specify a factor

Description

This special class can be passed as a ptype in order to specify that the result should be a factor that contains at least the specified levels.

Usage

partial_factor(levels = character())

Arguments

levels

Character vector of labels.

Examples

# Assert that `x` is a factor
vec_assert(factor("x"), partial_factor())

# Testing with `factor()` is too strict,
# because it tries to match the levels exactly
# rather than learning them from the data.
try(vec_assert(factor("x"), factor()))

# You can also enforce a minimum set of levels
try(vec_assert(factor("x"), partial_factor("y")))

vec_assert(factor(c("x", "y")), partial_factor("y"))

pf <- partial_factor(levels = c("x", "y"))
pf

vec_ptype_common(factor("v"), factor("w"), .ptype = pf)