R: Role Selection

has_role {recipes} | R Documentation

## Role Selection

### Description

`has_role`, `all_predictors`, and `all_outcomes` can be used to select variables in a formula that have certain roles. Similarly, `has_type`, `all_numeric`, and `all_nominal` are used to select columns based on their data type. See `selections()` for more details. `current_info` is an internal function that is unlikely to help users while the others have limited utility outside of step function arguments.

### Usage

    has_role(match = "predictor", roles = current_info()$roles)

    all_predictors(roles = current_info()$roles)

    all_outcomes(roles = current_info()$roles)

    has_type(match = "numeric", types = current_info()$types)

    all_numeric(types = current_info()$types)

    all_nominal(types = current_info()$types)

    current_info()

### Arguments

`match` | A single character string for the query. Exact matching is used (i.e. regular expressions won't work).
`roles` | A character string of roles for the current set of terms.
`types` | A character string of roles for the current set of data types.

### Value

Selector functions return an integer vector while `current_info` returns an environment with vectors `vars`, `roles`, and `types`.

### Examples

    data(biomass)

    rec <- recipe(biomass) %>%
      add_role(carbon, hydrogen, oxygen, nitrogen, sulfur,
               new_role = "predictor") %>%
      add_role(HHV, new_role = "outcome") %>%
      add_role(sample, new_role = "id variable") %>%
      add_role(dataset, new_role = "splitting indicator")
    recipe_info <- summary(rec)
    recipe_info

    has_role("id variable", roles = recipe_info$role)
    all_outcomes(roles = recipe_info$role)

[Package recipes version 0.1.2 Index]