import { BaseEstimator } from '../base';
export interface FeatureSelectingEstimator extends BaseEstimator {
    fit(X: number[][], y: number[]): void;
    predict?(X: number[][]): number[];
    score?(X: number[][], y: number[]): number;
}
export declare function estimatorImportances(estimator: FeatureSelectingEstimator): number[];
/** sklearn RFE transform_func="square": sum squared multiclass coefficients. */
export declare function estimatorImportancesSquared(estimator: FeatureSelectingEstimator): number[];
export declare function selectColumns(X: number[][], indices: number[]): number[][];
export declare function validateSelectionInput(X: number[][], y?: number[]): number;
export declare function resolveFeatureCount(value: number | undefined, nFeatures: number, fallback: number): number;
export declare function resolveStep(step: number, initialFeatureCount: number): number;