Struct PolynomialFeatures 

pub struct PolynomialFeatures<F> { /* private fields */ }

A stateless polynomial feature generator.

Generates all polynomial combinations of the input features up to the specified degree.

Configuration

• degree: maximum polynomial degree (default 2).
• interaction_only: if true, only cross-product terms are generated (no pure powers like a²). Default false.
• include_bias: if true, a constant column of ones is prepended. Default true.

Examples

use ferrolearn_preprocess::polynomial_features::PolynomialFeatures;
use ferrolearn_core::traits::Transform;
use ndarray::array;

let poly = PolynomialFeatures::<f64>::new(2, false, true).unwrap();
let x = array![[2.0, 3.0]];
let out = poly.transform(&x).unwrap();
// out = [[1, 2, 3, 4, 6, 9]]

Implementations

impl<F: Float + Send + Sync + 'static> PolynomialFeatures<F>

pub fn new( degree: usize, interaction_only: bool, include_bias: bool, ) -> Result<Self, FerroError>

Create a new PolynomialFeatures transformer.

Errors

Returns FerroError::InvalidParameter if degree == 0.

pub fn default_config() -> Self

Create a PolynomialFeatures with default settings: degree=2, interaction_only=false, include_bias=true.

pub fn degree(&self) -> usize

Return the configured degree.

pub fn interaction_only(&self) -> bool

Return whether only interaction terms are generated.

pub fn include_bias(&self) -> bool

Return whether a bias column is included.

Trait Implementations

impl<F: Clone> Clone for PolynomialFeatures<F>

fn clone(&self) -> PolynomialFeatures<F>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<F: Debug> Debug for PolynomialFeatures<F>

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

Formats the value using the given formatter.

impl<F: Float + Send + Sync + 'static> Default for PolynomialFeatures<F>

fn default() -> Self

Returns the “default value” for a type.

impl FittedPipelineTransformer for PolynomialFeatures<f64>

fn transform_pipeline(&self, x: &Array2<f64>) -> Result<Array2<f64>, FerroError>

Transform data using the pipeline interface.

Errors

Propagates errors from Transform::transform.

impl PipelineTransformer for PolynomialFeatures<f64>

fn fit_pipeline( &self, _x: &Array2<f64>, _y: &Array1<f64>, ) -> Result<Box<dyn FittedPipelineTransformer>, FerroError>

Fit the polynomial features transformer using the pipeline interface.

Because PolynomialFeatures is stateless, this simply boxes self as a FittedPipelineTransformer.

Errors

This implementation never returns an error.

impl<F: Float + Send + Sync + 'static> Transform<ArrayBase<OwnedRepr<F>, Dim<[usize; 2]>>> for PolynomialFeatures<F>

fn transform(&self, x: &Array2<F>) -> Result<Array2<F>, FerroError>

Generate polynomial and interaction features.

Errors

Returns FerroError::InvalidParameter if the input has zero columns.

type Output = ArrayBase<OwnedRepr<F>, Dim<[usize; 2]>>

The transformed output type.

type Error = FerroError

The error type returned by transform.