import type { DataCell } from '../types';
export declare const sampleSize: (array: any, n: number) => any[];
export declare const uniqBy: (array: any, key: string | ((item: any) => string)) => any;
export declare const isValidData: (data: DataCell) => boolean;
export declare function validateDate(date: any): boolean | {
    key: string;
    regex: RegExp;
    format: (match: string, year: string, month: string, day: string) => string;
};
export declare function convertStringToDateValue(stringDate: string): string;
export declare function average(data: any[], field?: string): number;
export declare function getIntersection(array1: DataCell[], array2: DataCell[]): DataCell[];
export declare const getStrFromArray: (array: string[]) => string;
export declare function findLastIndex(arr: any[], predicate: (value: any, index: number, array: any[]) => boolean): number;