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Convert Ordered Factors to Unordered Factors

Source: R/unorder.R
step_unorder.Rd

step_unorder creates a specification of a recipe step that will transform the data.

Usage

step_unorder(
  recipe,
  ...,
  role = NA,
  trained = FALSE,
  columns = NULL,
  skip = FALSE,
  id = rand_id("unorder")
)

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 variables for this step. See selections() for more details.

role

Not used by this step since no new variables are created.

trained

A logical to indicate if the quantities for preprocessing have been estimated.

columns

A character string of variable names that will be populated (eventually) by the terms argument.

skip

A logical. Should the step be skipped when the recipe is baked by bake()? While all operations are baked when prep() 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 skip = TRUE as it may affect the computations for subsequent operations.

id

A character string that is unique to this step to identify it.

Value

An updated version of recipe with the new step added to the sequence of any existing operations.

Details

The factors level order is preserved during the transformation.

Tidying

When you tidy() this step, a tibble with column terms (the columns that will be affected) is returned.

See also

Other dummy variable and encoding steps: step_bin2factor(), step_count(), step_date(), step_dummy_extract(), step_dummy_multi_choice(), step_dummy(), step_factor2string(), step_holiday(), step_indicate_na(), step_integer(), step_novel(), step_num2factor(), step_ordinalscore(), step_other(), step_regex(), step_relevel(), step_string2factor(), step_unknown()

Examples

lmh <- c("Low", "Med", "High")

examples <- data.frame(X1 = factor(rep(letters[1:4], each = 3)),
                       X2 = ordered(rep(lmh, each = 4),
                                    levels = lmh))

rec <- recipe(~ X1 + X2, data = examples)

factor_trans <- rec  %>%
  step_unorder(all_nominal_predictors())

factor_obj <- prep(factor_trans, training = examples)
#> Warning: `step_unorder` requires ordered factors. Variables X1 will be ignored.

transformed_te <- bake(factor_obj, examples)
table(transformed_te$X2, examples$X2)
#>       
#>        Low Med High
#>   Low    4   0    0
#>   Med    0   4    0
#>   High   0   0    4

tidy(factor_trans, number = 1)
#> # A tibble: 1 × 2
#>   terms                    id           
#>   <chr>                    <chr>        
#> 1 all_nominal_predictors() unorder_NRDyG
tidy(factor_obj, number = 1)
#> # A tibble: 1 × 2
#>   terms id           
#>   <chr> <chr>        
#> 1 X2    unorder_NRDyG