juice {recipes} | R Documentation

## Extract Finalized Training Set

### Description

As steps are estimated by `prep`, these operations are applied to the training set. Rather than running `bake` to duplicate this processing, this function will return variables from the processed training set.

### Usage

    juice(object, ..., composition = "tibble")

### Arguments

`object` | A `recipe` object that has been prepared with the option `retain = TRUE`.
`...` | One or more selector functions to choose which variables will be returned by the function. See `selections()` for more details. If no selectors are given, the default is to use `everything()`.
`composition` | Either "tibble", "matrix", "data.frame", or "dgCMatrix" for the format of the processed data set. Note that all computations during the baking process are done in a non-sparse format. Also, note that this argument should be called after any selectors and the selectors should only resolve to numeric columns (otherwise an error is thrown).

### Details

When preparing a recipe, if the training data set is retained using `retain = TRUE`, there is no need to `bake` the recipe to get the preprocessed training set.

`juice` will return the results of a recipes where all steps have been applied to the data, irrespective of the value of the step's `skip` argument.

### See Also

`recipe()` `prep.recipe()` `bake.recipe()`

### Examples

    data(biomass)

    biomass_tr <- biomass[biomass$dataset == "Training",]
    biomass_te <- biomass[biomass$dataset == "Testing",]

    rec <- recipe(HHV ~ carbon + hydrogen + oxygen + nitrogen + sulfur,
                  data = biomass_tr)

    sp_signed <- rec %>%
      step_center(all_predictors()) %>%
      step_scale(all_predictors()) %>%
      step_spatialsign(all_predictors())

    sp_signed_trained <- prep(sp_signed, training = biomass_tr, retain = TRUE)

    tr_values <- bake(sp_signed_trained, new_data = biomass_tr, all_predictors())
    og_values <- juice(sp_signed_trained, all_predictors())

    all.equal(tr_values, og_values)

[Package recipes version 0.1.5 Index]