Find valid categorical variables in a dataframe

Identifies valid and invalid character or factor variables. Invalid categorical predictors are those with a single category, or as many categories as cases (full-cardinality).

Usage

identify_categorical_variables(
  df = NULL,
  responses = NULL,
  predictors = NULL,
  quiet = FALSE,
  ...
)

Arguments

df

(required; dataframe, tibble, or sf) A dataframe with responses (optional) and predictors. Must have at least 10 rows for pairwise correlation analysis, and 10 * (length(predictors) - 1) for VIF. Default: NULL.

responses

(optional; character, character vector, or NULL) Name of one or several response variables in df. Default: NULL.

predictors

(required, character vector) Names of the predictors to identify. Default: NULL

quiet

(optional; logical) If FALSE, messages are printed. Default: FALSE.

...

(optional) Internal args (e.g. function_name for validate_arg_function_name, a precomputed correlation matrix m, or cross-validation args for preference_order).

Value

list:

• valid: character vector with valid categorical predictor names.

• invalid: character vector with invalid categorical predictor names due to degenerate cardinality (1 or nrow(df) categories).

See also

Other data_types: identify_logical_variables(), identify_numeric_variables(), identify_response_type(), identify_valid_variables(), identify_zero_variance_variables()

Author

Blas M. Benito, PhD

Examples

data(vi_smol, vi_predictors)

#create an invalid categorical
vi_smol$invalid_categorical <- "a"

x <- identify_categorical_variables(
  df = vi_smol,
  responses = "vi_categorical",
  predictors = vi_predictors
)

x$valid
#>  [1] "vi_categorical"     "koppen_zone"        "koppen_group"      
#>  [4] "koppen_description" "soil_type"          "biogeo_ecoregion"  
#>  [7] "biogeo_biome"       "biogeo_realm"       "country_name"      
#> [10] "continent"          "region"             "subregion"         
x$invalid
#> NULL