Struct FunctionTransformer 

pub struct FunctionTransformer { /* private fields */ }

Apply a user-defined function as a transformer, mirroring sklearn.preprocessing.FunctionTransformer.

The function is stored as a function pointer.

Serialization

The function pointers are not serialized. After deserialization call set_func to restore the function before calling transform or inverse_transform.

Implementations

impl FunctionTransformer

pub fn new(func: fn(&Matrix) -> Result<Matrix>) -> Self

Creates a new transformer applying func during transform.

pub fn with_inverse(self, inv_func: fn(&Matrix) -> Result<Matrix>) -> Self

Sets the inverse function used by inverse_transform.

pub fn set_func(&mut self, func: fn(&Matrix) -> Result<Matrix>)

Replaces the forward function (e.g. after deserialization).

pub fn set_inv_func(&mut self, inv_func: fn(&Matrix) -> Result<Matrix>)

Replaces the inverse function (e.g. after deserialization).

Trait Implementations

impl Clone for FunctionTransformer

fn clone(&self) -> FunctionTransformer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FunctionTransformer

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

Formats the value using the given formatter.

impl Default for FunctionTransformer

Default is an identity transformer (no function set).

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for FunctionTransformer

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Estimator for FunctionTransformer

impl FeatureNames for FunctionTransformer

fn feature_names_out(&self, input_features: Option<&[String]>) -> Vec<String>

Returns the output feature names given the optional input feature names.

impl Serialize for FunctionTransformer

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Transformer for FunctionTransformer

fn name(&self) -> &'static str

Name of the transformer, used for diagnostics.

fn fit(&mut self, x: &Matrix) -> Result<()>

Fit the transformer on training data.

fn transform(&self, x: &Matrix) -> Result<Matrix>

Transform data using fitted parameters.

fn inverse_transform(&self, x: &Matrix) -> Result<Matrix>

Reverse the transformation, recovering an approximation of the original input. Not all transformers support this; the default implementation returns an error.

fn is_fitted(&self) -> bool

Whether the transformer has been fitted.

fn fit_transform(&mut self, x: &Matrix) -> Result<Matrix>

Convenience: fit then transform.

fn fit_with_target(&mut self, x: &Matrix, _y: &[f64]) -> Result<()>

Fit the transformer with supervised target values when they are available. Unsupervised transformers ignore y by default. Supervised feature selectors override this method, allowing them to live safely in a SupervisedPipeline.