Enum KernelExpr 

pub enum KernelExpr {
    Base(BaseKernel),
    Sum(Box<KernelExpr>, Box<KernelExpr>),
    Product(Box<KernelExpr>, Box<KernelExpr>),
}

A compositional kernel expression formed by summing or multiplying sub-kernels.

The expression depth is defined recursively:

• Base(k) has depth 0.
• Sum(a, b) and Product(a, b) have depth 1 + max(depth(a), depth(b)).

Variants

Base(BaseKernel)

A single base kernel.

Sum(Box<KernelExpr>, Box<KernelExpr>)

Sum of two kernel expressions: k(x, y) = a(x, y) + b(x, y).

Product(Box<KernelExpr>, Box<KernelExpr>)

Product of two kernel expressions: k(x, y) = a(x, y) · b(x, y).

Implementations

impl KernelExpr

pub fn eval(&self, x1: f64, x2: f64) -> f64

Evaluate the kernel at (x1, x2).

pub fn description(&self) -> String

Human-readable description, e.g. "RBF + Periodic × Linear".

pub fn depth(&self) -> usize

Compute the full depth of this expression tree.

Trait Implementations

impl Clone for KernelExpr

fn clone(&self) -> KernelExpr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KernelExpr

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

Formats the value using the given formatter.