healthcareai (version 2.1.1)

step_date_hcai: Date Feature Generator

Description

`step_date_hcai` creates a a *specification* of a recipe step that will convert date data into one or more factor or numeric variables. It is a copy of `recipes::step_date` but will try to guess the date format of columns with the "_DTS" suffix.

Usage

step_date_hcai(recipe, ..., role = "predictor", trained = FALSE,
  features = c("dow", "month", "year"), abbr = TRUE, label = TRUE,
  ordinal = FALSE, columns = NULL, skip = FALSE)
# S3 method for step_date_hcai
tidy(x, ...)

Arguments

recipe

A recipe object. The step will be added to the sequence of operations for this recipe.

...

One or more selector functions to choose which variables that will be used to create the new variables. The selected variables should have class `Date` or `POSIXct`. See [selections()] for more details. For the `tidy` method, these are not currently used.

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.

trained

A logical to indicate if the number of NA values have been counted in preprocessing.

features

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

abbr

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

label

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

ordinal

A logical: should factors be ordered? Only available for features `month` or `dow`.

columns

A character string of variables that will be used as inputs. This field is a placeholder and will be populated once [prep.recipe()] is used.

skip

A logical. Should the step be skipped when the recipe is baked?

x

A `step_date_hcai` object.

Value

For `step_date_hcai`, an updated version of recipe with the new step added to the sequence of existing steps (if any). For the `tidy` method, a tibble with columns `terms` (the selectors or variables selected), `value` (the feature names), and `ordinal` (a logical).

Details

Unlike other steps, `step_date_hcai` does *not* remove the original date variables. [step_rm()] can be used for this purpose.

Examples

# NOT RUN {
library(lubridate)
library(recipes)

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_hcai(all_predictors())

date_rec <- prep(date_rec, training = examples)

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

# }