Enum GeometricKernel 

pub enum GeometricKernel {
    Heat {
        sigma: f64,
    },
    SphericalHarmonic {
        bandwidth: usize,
        sigma: f64,
    },
    Matern {
        nu: f64,
        length_scale: f64,
    },
}

Kernel type for geometric (manifold) RBF interpolation.

Variants

Heat

Heat kernel: k(d) = exp(-d² / σ²).

Corresponds to the fundamental solution of the heat equation on the manifold.

Fields

sigma: f64

Bandwidth parameter σ > 0.

SphericalHarmonic

Zonal kernel via truncated spherical harmonic expansion.

k(θ) = Σ_{l=0}^{L} (2l+1)/(4π) · exp(-l(l+1)σ²) · P_l(cos θ)

where P_l are Legendre polynomials. Only meaningful on S².

Fields

bandwidth: usize

Maximum angular frequency (bandwidth).

sigma: f64

Diffusion time / decay parameter σ > 0.

Matern

Matérn kernel using geodesic distance.

Supports ν = 0.5 (exponential), 1.5, 2.5; falls back to Gaussian for other ν.

Fields

nu: f64

Smoothness parameter ν (typically 0.5, 1.5, or 2.5).

length_scale: f64

Length-scale parameter ℓ > 0.

Trait Implementations

impl Clone for GeometricKernel

fn clone(&self) -> GeometricKernel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GeometricKernel

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

Formats the value using the given formatter.