unknown() creates an expression used to signify that the value will be specified at a later time.

unknown()

is_unknown(x)

has_unknowns(object)

Arguments

x

An object or vector or objects to test for unknown-ness.

object

An object of class param.

Value

unknown() returns expression value for unknown().

is_unknown() returns a vector of logicals as long as x that are TRUE is the element of x is unknown, and FALSE otherwise.

has_unknowns() returns a single logical indicating if the range of a param object has any unknown values.

Examples

# Just returns an expression unknown()
#> unknown()
# Of course, true! is_unknown(unknown())
#> [1] TRUE
# Create a range with a minimum of 1 # and an unknown maximum range <- c(1, unknown()) range
#> [[1]] #> [1] 1 #> #> [[2]] #> unknown() #>
# The first value is known, the # second is not is_unknown(range)
#> [1] FALSE TRUE
# mtry()'s maximum value is not known at # creation time has_unknowns(mtry())
#> [1] TRUE