Enum DiscretizeMethod 

pub enum DiscretizeMethod {
    Tustin,
    ExpTrapezoidal,
}

Available on crate feature alloc only.

Discretization method for ComplexDiagonalSSM.

Selects how the continuous-time complex eigenvalue A is mapped to a discrete-time transition coefficient α.

Variants

Tustin

Bilinear (Tustin) transform: S4-style, 2-term recurrence.

α = (I + Δ/2·A)(I - Δ/2·A)⁻¹. Maps left-half s-plane to unit disk exactly. Good for S4-style oscillatory SSMs.

ExpTrapezoidal

Exponential-trapezoidal: Mamba-3 spec, 3-term recurrence.

α = exp(Δ·A). Stronger stability (no Δ constraint). Requires lambda per step — either fixed or data-dependent from the model.

See exp_trapezoidal_complex for the full 3-term derivation. (Lahoti et al., arXiv:2603.15569, ICLR 2026, Table 1.)

Trait Implementations

impl Clone for DiscretizeMethod

fn clone(&self) -> DiscretizeMethod

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DiscretizeMethod

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

Formats the value using the given formatter.

impl PartialEq for DiscretizeMethod

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for DiscretizeMethod

impl Eq for DiscretizeMethod

impl StructuralPartialEq for DiscretizeMethod