Struct FrequencyEncoder 

pub struct FrequencyEncoder { /* private fields */ }

FrequencyEncoder for converting categorical features to frequency counts

This transformer converts categorical features into their frequency of occurrence in the training data. High-frequency categories get higher values, which can be useful for models that can leverage frequency information.

Implementations

impl FrequencyEncoder

pub fn new( normalize: bool, handleunknown: &str, unknownvalue: f64, ) -> Result<Self>

Creates a new FrequencyEncoder

Arguments

• normalize - Whether to normalize frequencies to [0, 1] range
• handleunknown - How to handle unknown categories (‘error’, ‘ignore’, or ‘use_encoded_value’)
• unknownvalue - Value to use for unknown categories (when handleunknown=“use_encoded_value”)

Returns

• Result<FrequencyEncoder> - The new encoder instance

pub fn with_defaults() -> Self

Creates a FrequencyEncoder with default settings

pub fn with_normalization() -> Self

Creates a FrequencyEncoder with normalized frequencies

pub fn fit<S>(&mut self, x: &ArrayBase<S, Ix2>) -> Result<()>

where S: Data, S::Elem: Float + NumCast,

Fits the FrequencyEncoder to the input data

Arguments

• x - The input categorical data, shape (n_samples, n_features)

Returns

• Result<()> - Ok if successful, Err otherwise

pub fn transform<S>(&self, x: &ArrayBase<S, Ix2>) -> Result<Array2<f64>>

where S: Data, S::Elem: Float + NumCast,

Transforms the input data using the fitted FrequencyEncoder

Arguments

• x - The input categorical data, shape (n_samples, n_features)

Returns

• Result<Array2<f64>> - The frequency-encoded data

pub fn fit_transform<S>(&mut self, x: &ArrayBase<S, Ix2>) -> Result<Array2<f64>>

where S: Data, S::Elem: Float + NumCast,

Fits the encoder and transforms the data in one step

Arguments

• x - The input categorical data

Returns

• Result<Array2<f64>> - The frequency-encoded data

pub fn is_fitted(&self) -> bool

Returns whether the encoder has been fitted

pub fn frequency_maps(&self) -> Option<&Vec<HashMap<u64, f64>>>

Returns the learned frequency mappings if fitted

Trait Implementations

impl Clone for FrequencyEncoder

fn clone(&self) -> FrequencyEncoder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FrequencyEncoder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.