Struct MEMDConfig 

#[non_exhaustive]
pub struct MEMDConfig {
    pub num_directions: usize,
    pub max_imfs: usize,
    pub sifting_tolerance: f64,
    pub sifting_tolerance_strict: f64,
    pub sifting_fraction: f64,
    pub max_sifting_iterations: usize,
    pub direction_strategy: DirectionStrategy,
    pub random_seed: Option<u64>,
    pub end_effect_strategy: EndEffectStrategy,
}

Configuration for memd.

Builder-style setters mirror super::emd::EMDConfig; the struct is #[non_exhaustive] so downstream callers must construct via MEMDConfig::default (or one of the preset constructors) and chain with_* methods.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

num_directions: usize

Number of direction vectors. Must be ≥ 1. Rehman & Mandic (2010) recommend ≥ 2·n for n ≤ 4 and K = 64 as a sweet-spot default for 4 ≤ n ≤ 8; for very high-dimensional inputs (n ≫ 8, e.g. 64-channel EEG arrays) prefer K ≥ 2·n. Default is 64.

Degenerate case: K = 1 reduces MEMD to univariate EMD on a single fixed projection and loses the joint scale-alignment property that motivates MEMD in the first place. Permitted but not recommended.

max_imfs: usize

Maximum number of IMFs to extract. Default 8.

sifting_tolerance: f64

Rilling α — primary tolerance on per-sample σ(t) = |mean|/amplitude. Stopping requires σ(t) < α on at least 1 − sifting_fraction of the (channel, sample) population. Default 0.075.

sifting_tolerance_strict: f64

Rilling β — strict bound; stopping requires σ(t) < β on all (channel, sample) points. Default 0.75 (10·α convention).

sifting_fraction: f64

Rilling fraction — maximum fraction of points allowed to exceed α (provided they still satisfy β). Default 0.05.

max_sifting_iterations: usize

Maximum sifting iterations per IMF. Default 100.

direction_strategy: DirectionStrategy

How to generate direction vectors. Default DirectionStrategy::Hammersley.

random_seed: Option<u64>

Seed used by DirectionStrategy::Uniform; ignored under Hammersley. None falls back to a nanos-based seed (non-deterministic across runs).

end_effect_strategy: EndEffectStrategy

End-effect strategy applied to per-channel cubic-spline envelope construction. Default is EndEffectStrategy::MirrorExtrema{ num_extrema: 3 } (Rilling, Flandrin & Gonçalves 2003), matching the v2.0.0 super::emd::EMDConfig default.

Only EndEffectStrategy::LinearSlope and EndEffectStrategy::MirrorExtrema are accepted by memd. The other variants mix conventions that have no basis in the MEMD literature when ported from univariate EMD:

• EndEffectStrategy::SymmetricExtension reflects channel-residue y-values around the channel’s boundary samples (2·data[boundary] − data[idx]), but the extrema indices come from the projection, so the reflected anchor pairs values from one signal with positions from another.
• EndEffectStrategy::AutoRegressive fits an AR model on the channel residue and extends it past the boundary, but the interior knot positions are projection-derived; the exterior AR-extension extrema and the interior projection extrema are computed under different criteria and cannot be cleanly stitched.

Passing either rejected variant returns WaveletError::InvalidParameter from memd.

Implementations

impl MEMDConfig

pub fn with_num_directions(self, num_directions: usize) -> Self

Override the number of direction vectors.

pub fn with_max_imfs(self, max_imfs: usize) -> Self

Override the maximum IMF count.

pub fn with_sifting_tolerance(self, sifting_tolerance: f64) -> Self

Override the Rilling α tolerance.

pub fn with_sifting_tolerance_strict( self, sifting_tolerance_strict: f64, ) -> Self

Override the Rilling β strict tolerance.

pub fn with_sifting_fraction(self, sifting_fraction: f64) -> Self

Override the Rilling fraction.

pub fn with_max_sifting_iterations(self, max_sifting_iterations: usize) -> Self

Override the per-IMF sifting iteration cap.

pub fn with_direction_strategy( self, direction_strategy: DirectionStrategy, ) -> Self

Choose DirectionStrategy.

pub fn with_seed(self, seed: u64) -> Self

Set the RNG seed for DirectionStrategy::Uniform.

This only sets random_seed — it does not change direction_strategy. Under the default DirectionStrategy::Hammersley the seed is ignored (Hammersley is deterministic). To get seeded reproducibility, pair this with MEMDConfig::with_direction_strategy( DirectionStrategy::Uniform) — order does not matter:

MEMDConfig::default()
    .with_direction_strategy(DirectionStrategy::Uniform)
    .with_seed(42)

pub fn with_end_effect_strategy( self, end_effect_strategy: EndEffectStrategy, ) -> Self

Choose the end-effect strategy used during per-channel envelope construction.

Trait Implementations

impl Clone for MEMDConfig

fn clone(&self) -> MEMDConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MEMDConfig

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

Formats the value using the given formatter.

impl Default for MEMDConfig

fn default() -> Self

Returns the “default value” for a type.