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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/num2factor.R
\name{step_num2factor}
\alias{step_num2factor}
\alias{tidy.step_num2factor}
\title{Convert Numbers to Factors}
\usage{
step_num2factor(
recipe,
...,
role = NA,
transform = function(x) x,
trained = FALSE,
levels,
ordered = FALSE,
skip = FALSE,
id = rand_id("num2factor")
)
\method{tidy}{step_num2factor}(x, ...)
}
\arguments{
\item{recipe}{A recipe object. The step will be added to the
sequence of operations for this recipe.}
\item{...}{One or more selector functions to choose which variables will be
converted to factors. See \code{\link[=selections]{selections()}} for more details. For the \code{tidy}
method, these are not currently used.}
\item{role}{Not used by this step since no new variables are created.}
\item{transform}{A function taking a single argument \code{x} that can be used
to modify the numeric values prior to determining the levels (perhaps using
\code{\link[base:integer]{base::as.integer()}}). The output of a function should be an integer that
corresponds to the value of \code{levels} that should be assigned. If not an
integer, the value will be converted to an integer during \code{bake()}.}
\item{trained}{A logical to indicate if the quantities for
preprocessing have been estimated.}
\item{levels}{A character vector of values that will be used as the levels.
These are the numeric data converted to character and ordered. This is
modified once \code{\link[=prep.recipe]{prep.recipe()}} is executed.}
\item{ordered}{A single logical value; should the factor(s) be ordered?}
\item{skip}{A logical. Should the step be skipped when the
recipe is baked by \code{\link[=bake.recipe]{bake.recipe()}}? While all operations are baked
when \code{\link[=prep.recipe]{prep.recipe()}} is run, some operations may not be able to be
conducted on new data (e.g. processing the outcome variable(s)).
Care should be taken when using \code{skip = TRUE} as it may affect
the computations for subsequent operations}
\item{id}{A character string that is unique to this step to identify it.}
\item{x}{A \code{step_num2factor} object.}
}
\value{
An updated version of \code{recipe} with the new step added to the
sequence of existing steps (if any). For the \code{tidy} method, a tibble with
columns \code{terms} (the selectors or variables selected) and \code{ordered}.
}
\description{
\code{step_num2factor} will convert one or more numeric vectors to factors
(ordered or unordered). This can be useful when categories are encoded as
integers.
}
\examples{
library(dplyr)
library(modeldata)
data(attrition)
attrition \%>\%
group_by(StockOptionLevel) \%>\%
count()
amnt <- c("nothin", "meh", "some", "copious")
rec <-
recipe(Attrition ~ StockOptionLevel, data = attrition) \%>\%
step_num2factor(
StockOptionLevel,
transform = function(x) x + 1,
levels = amnt
)
encoded <- rec \%>\% prep() \%>\% bake(new_data = NULL)
table(encoded$StockOptionLevel, attrition$StockOptionLevel)
# an example for binning
binner <- function(x) {
x <- cut(x, breaks = 1000 * c(0, 5, 10, 20), include.lowest = TRUE)
# now return the group number
as.numeric(x)
}
inc <- c("low", "med", "high")
rec <-
recipe(Attrition ~ MonthlyIncome, data = attrition) \%>\%
step_num2factor(
MonthlyIncome,
transform = binner,
levels = inc,
ordered = TRUE
) \%>\%
prep()
encoded <- bake(rec, new_data = NULL)
table(encoded$MonthlyIncome, binner(attrition$MonthlyIncome))
# What happens when a value is out of range?
ceo <- attrition \%>\% slice(1) \%>\% mutate(MonthlyIncome = 10^10)
bake(rec, ceo)
}
\seealso{
\code{\link[=step_factor2string]{step_factor2string()}}, \code{\link[=step_string2factor]{step_string2factor()}}, \code{\link[=step_dummy]{step_dummy()}}
}
\concept{factors}
\concept{preprocessing}
\concept{variable_encodings}
\keyword{datagen}
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