Struct WaveletTransform 

pub struct WaveletTransform { /* private fields */ }

Wavelet Transform extractor

Performs discrete wavelet transform with configurable wavelet types and decomposition levels. Extracts energy-based features from the resulting coefficients at each level.

Implementations

impl WaveletTransform

pub fn new() -> Self

Create a new wavelet transform extractor

pub fn wavelet(self, wavelet: String) -> Self

Set the wavelet type

Supported wavelets include:

• “haar”: Haar wavelet (simplest)
• “db4”: Daubechies 4-tap wavelet
• “db8”: Daubechies 8-tap wavelet
• Additional wavelets can be implemented as needed

pub fn wavelet_type(self, wavelet_type: String) -> Self

Set the wavelet type (alternative method name)

pub fn levels(self, levels: usize) -> Self

Set the number of decomposition levels

More levels provide better frequency resolution but require longer signals. The maximum useful levels is approximately log2(signal_length).

pub fn mode(self, mode: String) -> Self

Set the boundary mode for decomposition

Supported modes:

• “symmetric”: Symmetric boundary extension
• “zero”: Zero padding
• “periodic”: Periodic boundary conditions

pub fn extract_features( &self, signal: &ArrayView1<'_, f64>, ) -> SklResult<Array1<f64>>

Extract wavelet-based features from signal

Returns energy features from each decomposition level:

• Detail energies at each level (high-frequency components)
• Final approximation energy (low-frequency component)

pub fn decompose( &self, signal: &ArrayView1<'_, f64>, ) -> SklResult<Vec<(Array1<f64>, Array1<f64>)>>

Perform complete wavelet decomposition

Returns the full decomposition tree with coefficients at each level. Useful for reconstruction or more detailed analysis.

pub fn approximation_coefficients( &self, signal: &ArrayView1<'_, f64>, ) -> SklResult<Array1<f64>>

Get approximation coefficients at the final level

pub fn detail_coefficients_at_level( &self, signal: &ArrayView1<'_, f64>, target_level: usize, ) -> SklResult<Array1<f64>>

Get detail coefficients at a specific level

pub fn energy_distribution( &self, signal: &ArrayView1<'_, f64>, ) -> SklResult<Array1<f64>>

Compute relative energy distribution across levels

pub fn wavelet_entropy(&self, signal: &ArrayView1<'_, f64>) -> SklResult<f64>

Compute entropy of wavelet coefficients

pub fn transform(&self, signal: &ArrayView1<'_, f64>) -> SklResult<Vec<f64>>

Perform wavelet transform on the signal

Returns the wavelet coefficients.

pub fn inverse_transform(&self, _coefficients: &[f64]) -> SklResult<Array1<f64>>

Perform inverse wavelet transform

Reconstructs the original signal from wavelet coefficients.

Trait Implementations

impl Clone for WaveletTransform

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WaveletTransform

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

Formats the value using the given formatter.

impl Default for WaveletTransform

fn default() -> Self

Returns the “default value” for a type.