//! Kernel Methods
//!
//! This module provides kernel-based algorithms for nonlinear machine learning:
//!
//! - **Kernel Functions** (`kernels`): A library of kernel functions (Linear, Polynomial,
//! RBF/Gaussian, Laplacian, Sigmoid), Gram matrix computation, and kernel centering.
//!
//! - **Kernel PCA** (`kpca`): Nonlinear dimensionality reduction via the kernel trick,
//! with pre-image estimation and automatic parameter selection.
//!
//! - **Kernel Ridge Regression** (`kernel_ridge`): Tikhonov-regularized regression in
//! kernel space, with closed-form LOO-CV and multi-output support.
/// Kernel functions library (Linear, Polynomial, RBF, Laplacian, Sigmoid)
/// Kernel PCA for nonlinear dimensionality reduction
/// Kernel Ridge Regression
// Re-exports for convenience
pub use KernelRidgeRegression;
pub use ;
pub use KernelPCA;