import { RegressorBase } from '../base';
import { Params } from '../base/estimator';
export type KernelRidgeKernel = 'linear' | 'poly' | 'rbf' | 'sigmoid' | 'cosine';
export interface KernelRidgeProps {
    alpha?: number;
    kernel?: KernelRidgeKernel;
    gamma?: number | null;
    degree?: number;
    coef0?: number;
}
export declare class KernelRidge extends RegressorBase {
    private alpha;
    private kernel;
    private gamma;
    private degree;
    private coef0;
    private trainingState;
    private dualCoefState;
    private nFeaturesState;
    constructor(props?: KernelRidgeProps);
    getParams(): Params;
    private similarity;
    fit(X: number[][], y: number[]): void;
    predict(X: number[][]): number[];
    get dualCoef(): number[];
    get XFit(): number[][];
}