Enum SpectralMethod 

pub enum SpectralMethod {
    Lanczos,
    Rff,
    Eml,
}

Algorithm used to estimate algebraic connectivity (lambda₂).

Decision rule (default policy)

Node count n	Path	Rationale
n < 10_000	SpectralMethod::Lanczos	Sparse O(k·m) is accurate and cheap enough; preferred when Fiedler quality matters
10_000 ≤ n < 100_000	SpectralMethod::Rff	O(m) random Fourier features; ~3–6× faster than Lanczos with ~5% accuracy loss
n ≥ 100_000	SpectralMethod::Eml	O(1) feature model for tick-rate budgets; re-train from occasional RFF/Lanczos

Thresholds are SPECTRAL_RFF_MIN_NODES and SPECTRAL_EML_MIN_NODES. Override via explicit spectral_analysis / spectral_analysis_rff / EmlCoherenceModel::predict when a caller knows better.

See docs/benchmarks/results.md (WEFT-361) and the spectral_lambda2_bench harness for measured latency/accuracy.

Variants

Lanczos

Sparse Lanczos on the graph Laplacian (reference / small-n path).

Rff

Random Fourier Feature Laplacian estimator (large-n exact path).

Eml

O(1) EML coherence model from graph statistics (fast path).

Implementations

impl SpectralMethod

pub fn as_str(self) -> &'static str

Stable string label for logs and JSON bench output.

Trait Implementations

impl Clone for SpectralMethod

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SpectralMethod

impl Debug for SpectralMethod

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

Formats the value using the given formatter.

impl Eq for SpectralMethod

impl Hash for SpectralMethod

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for SpectralMethod

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SpectralMethod