Normalization of Character VariablesSource:
step_text_normalization() creates a specification of a recipe step that
will perform Unicode Normalization on character variables.
step_text_normalization( recipe, ..., role = NA, trained = FALSE, columns = NULL, normalization_form = "nfc", skip = FALSE, id = rand_id("text_normalization") )
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 are affected by the step. See
recipes::selections()for more details.
Not used by this step since no new variables are created.
A logical to indicate if the quantities for preprocessing have been estimated.
A character string of variable names that will be populated (eventually) by the
termsargument. This is
NULLuntil the step is trained by
A single character string determining the Unicode Normalization. Must be one of "nfc", "nfd", "nfkd", "nfkc", or "nfkc_casefold". Defaults to "nfc". See
stringi::stri_trans_nfc()for more details.
A logical. Should the step be skipped when the recipe is baked by
recipes::bake.recipe()? While all operations are baked when
recipes::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
skip = FALSE.
A character string that is unique to this step to identify it.
An updated version of
recipe with the new step added
to the sequence of existing steps (if any).
tidy() this step, a tibble with columns
(the selectors or variables selected) and
normalization_form (type of
step_texthash() for feature hashing.
library(recipes) sample_data <- tibble(text = c("sch\U00f6n", "scho\U0308n")) rec <- recipe(~., data = sample_data) %>% step_text_normalization(text) prepped <- rec %>% prep() bake(prepped, new_data = NULL, text) %>% slice(1:2) #> # A tibble: 2 × 1 #> text #> <fct> #> 1 schön #> 2 schön bake(prepped, new_data = NULL) %>% slice(2) %>% pull(text) #>  schön #> Levels: schön tidy(rec, number = 1) #> # A tibble: 1 × 3 #> terms normalization_form id #> <chr> <chr> <chr> #> 1 text NA text_normalization_j8gw4 tidy(prepped, number = 1) #> # A tibble: 1 × 3 #> terms normalization_form id #> <chr> <chr> <chr> #> 1 text nfc text_normalization_j8gw4