% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/date.R
\name{step_date}
\alias{step_date}
\alias{tidy.step_date}
\title{Date Feature Generator}
\usage{
step_date(
  recipe,
  ...,
  role = "predictor",
  trained = FALSE,
  features = c("dow", "month", "year"),
  abbr = TRUE,
  label = TRUE,
  ordinal = FALSE,
  columns = NULL,
  skip = FALSE,
  id = rand_id("date")
)

\method{tidy}{step_date}(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 that will be used to create the new variables. The
selected variables should have class \code{Date} or
\code{POSIXct}. See \code{\link[=selections]{selections()}} for more details.
For the \code{tidy} method, these are not currently used.}

\item{role}{For model terms created by this step, what analysis
role should they be assigned?. By default, the function assumes
that the new variable columns created by the original variables
will be used as predictors in a model.}

\item{trained}{A logical to indicate if the quantities for
preprocessing have been estimated.}

\item{features}{A character string that includes at least one
of the following values: \code{month}, \code{dow} (day of week),
\code{doy} (day of year), \code{week}, \code{month},
\code{decimal} (decimal date, e.g. 2002.197), \code{quarter},
\code{semester}, \code{year}.}

\item{abbr}{A logical. Only available for features \code{month}
or \code{dow}. \code{FALSE} will display the day of the week as
an ordered factor of character strings, such as "Sunday".
\code{TRUE} will display an abbreviated version of the label,
such as "Sun". \code{abbr} is disregarded if \code{label = FALSE}.}

\item{label}{A logical. Only available for features
\code{month} or \code{dow}. \code{TRUE} will display the day of
the week as an ordered factor of character strings, such as
"Sunday." \code{FALSE} will display the day of the week as a
number.}

\item{ordinal}{A logical: should factors be ordered? Only
available for features \code{month} or \code{dow}.}

\item{columns}{A character string of variables that will be
used as inputs. This field is a placeholder and will be
populated once \code{\link[=prep.recipe]{prep.recipe()}} is used.}

\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_date} object.}
}
\value{
For \code{step_date}, an updated version of 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), \code{value} (the feature
names), and \code{ordinal} (a logical).
}
\description{
\code{step_date} creates a \emph{specification} of a recipe
step that will convert date data into one or more factor or
numeric variables.
}
\details{
Unlike other steps, \code{step_date} does \emph{not}
remove the original date variables. \code{\link[=step_rm]{step_rm()}} can be
used for this purpose.
}
\examples{
library(lubridate)

examples <- data.frame(Dan = ymd("2002-03-04") + days(1:10),
                       Stefan = ymd("2006-01-13") + days(1:10))
date_rec <- recipe(~ Dan + Stefan, examples) \%>\%
   step_date(all_predictors())

tidy(date_rec, number = 1)

date_rec <- prep(date_rec, training = examples)

date_values <- bake(date_rec, new_data = examples)
date_values

tidy(date_rec, number = 1)

}
\seealso{
\code{\link[=step_holiday]{step_holiday()}} \code{\link[=step_rm]{step_rm()}}
\code{\link[=recipe]{recipe()}} \code{\link[=prep.recipe]{prep.recipe()}}
\code{\link[=bake.recipe]{bake.recipe()}}
}
\concept{dates}
\concept{model_specification}
\concept{preprocessing}
\concept{variable_encodings}
\keyword{datagen}
