Struct MaternBasisSpec 

pub struct MaternBasisSpec {
    pub center_strategy: CenterStrategy,
    pub periodic: Option<Vec<Option<f64>>>,
    pub length_scale: f64,
    pub nu: MaternNu,
    pub include_intercept: bool,
    pub double_penalty: bool,
    pub identifiability: MaternIdentifiability,
    pub aniso_log_scales: Option<Vec<f64>>,
    pub nullspace_shrinkage_survived: Option<bool>,
}

Matérn basis configuration.

Fields

center_strategy: CenterStrategy

periodic: Option<Vec<Option<f64>>>

length_scale: f64

nu: MaternNu

include_intercept: bool

double_penalty: bool

identifiability: MaternIdentifiability

aniso_log_scales: Option<Vec<f64>>

Per-axis anisotropy log-scales η_a (contrasts with Ση_a = 0).

This implements geometric anisotropy: Λ = κA where A = diag(exp(η_a)), det(A) = 1. The kernel is evaluated at r = κ|Ah| instead of r = κ|h|. The decomposition preserves the isotropic scaling law for global κ and adds d−1 shape parameters for directional relevance.

Conditional positive definiteness is preserved under any invertible linear coordinate transform (Schoenberg), so the kernel remains valid.

When Some, the distance is r = √(Σ_a exp(2η_a) · (x_a - c_a)²). When None, isotropic distance r = ‖x - c‖ is used.

nullspace_shrinkage_survived: Option<bool>

Frozen double-penalty nullspace-shrinkage decision (gam#787/#860).

None (the default, and the cold-build value) = decide whether to emit the DoublePenaltyNullspace candidate via the κ-dependent spectral test in build_nullspace_shrinkage_penalty. Some(b) = force the decision (set by the freeze step from the bootstrap-κ build, mirrored from MaternIdentifiability::FrozenTransform) so the learned-penalty count stays invariant as the κ-optimizer rebuilds the design at each trial length-scale. Only consulted when double_penalty is true.

Trait Implementations

impl Clone for MaternBasisSpec

fn clone(&self) -> MaternBasisSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MaternBasisSpec

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MaternBasisSpec

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for MaternBasisSpec

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

where __S: Serializer,

Serialize this value into the given Serde serializer.