import { TransformerBase } from '../base/transformer';
import { Params } from '../base/estimator';
export interface PCAProps {
    /** number of components to keep; null keeps all features */
    nComponents?: number | null;
}
export declare class PCA extends TransformerBase {
    protected nComponents: number | null;
    protected components: number[][];
    protected mean: number[];
    protected explainedVariance: number[];
    constructor(props?: PCAProps);
    /** @deprecated positional form; prefer the props-object constructor */
    constructor(nComponents?: number | null);
    getParams(): Params;
    fit(X: number[][]): void;
    transform(X: number[][]): number[][];
    fitTransform(X: number[][]): number[][];
    inverseTransform(X: number[][]): number[][];
    getComponents(): number[][];
    getMean(): number[];
    getExplainedVariance(): number[];
}