/**
 * generate random int between [low, high)
 * @param low
 * @param high
 */
export declare function randomInt(low: number, high: number): number;
/**
 * random n not repeat int between [low, high)
 * @param low
 * @param high
 * @param n
 */
export declare function randomNIntNotRepeat(low: number, high: number, n: number): number[];
/**
 * select n items of data
 * @param data
 * @param n
 */
export declare function sample<T>(data: T[], n: number): T[];
/**
 * sum
 * @param data
 */
export declare function sum(data: number[]): number;
/**
 * calculate mean value of data
 * @param data
 */
export declare function mean(data: number[]): number;
/**
 * calculate ma line of data with window n
 * @param data
 * @param n
 */
export declare function ma(data: number[], n: number): number[];
/**
 * ema
 * @param data
 * @param n
 */
export declare function ema(data: number[], n: number): number[];
/**
 * dif of two array
 * @param d1
 * @param d2
 */
export declare function dif(d1: number[], d2: number[]): number[];
/**
 * array * v
 * @param data
 * @param v
 */
export declare function multiply(data: number[], v: number | number[]): number[];
/**
 * data + v
 * @param data
 * @param v
 */
export declare function add(data: number[], v: number | number[]): number[];
/**
 * macd
 * @param data
 * @param nShort
 * @param nLong
 * @param nDif
 */
export declare function macd(data: number[], nShort: number, nLong: number, nDif: number): number[];
/**
 * normalize data to [low, high]
 * @param data
 * @param low
 * @param high
 */
export declare function normalize(data: number[], low: number, high: number): number[];
/**
 * round float
 * @param data
 * @param n
 */
export declare function round(data: number, n: number): number;
/**
 * calculate stock brokerage
 * @param exchangeType
 * @param amount
 * @param price
 */
export declare function brokerage(exchangeType: 'buy' | 'sell', amount: number, price: number): number;
/**
 * return the range between [start, end) with step
 * @param start
 * @param end
 * @param step
 */
export declare function range(start: number, end: number, step: number): number[];
/**
 * multiply by position
 * @param {number[]} a1
 * @param {number[]} a2
 * @return {number}
 */
export declare function dotMultiply(a1: number[], a2: number[]): number;
/**
 * calculate variance of data
 * @param {number[]} data
 * @return {number}
 */
export declare function variance(data: number[]): number;
/**
 * calculate standard deviation of data
 * @param {number[]} data
 * @return {number}
 */
export declare function std(data: number[]): number;
/**
 * corvation of a1 and a2
 * @param {number[]} a1
 * @param {number[]} a2
 * @return {number}
 */
export declare function covariance(a1: number[], a2: number[]): number;
/**
 * calculate the correlation of a1 and a2
 * @param {number[]} a1
 * @param {number[]} a2
 * @return {number}
 */
export declare function correlation(a1: number[], a2: number[]): number;
/**
 * calculate r square of label and predictLabel
 * @param {number[]} label
 * @param {number[]} predictLabel
 * @return {number}
 */
export declare function r2(label: number[], predictLabel: number[]): number;
/**
 * judge whether a and b is closeable
 * @param {number} a
 * @param {number} b
 * @param {number} tolerance
 * @return {boolean}
 */
export declare const isCloseable: (a: number, b: number, tolerance?: number | undefined) => boolean;
/**
 * convert num to binary number
 * @param {number} num
 * @param {number} bitLen
 * @return {number[]}
 */
export declare const toBNumber: (num: number, bitLen: number) => number[];
/**
 * convert color num to hex number array
 * @param {number} num
 * @return {number[]}
 */
export declare const convertColorToHexNumberArray: (num: number) => number[];
/**
 * convert color num to hex char array
 * @param {number} num
 * @return {string[]}
 */
export declare const convertColorToHexCharArray: (num: number) => string[];
/**
 * parse hex string into number, return NaN if parse num failed
 * @param {string} num
 * @return {number}
 */
export declare const parseHexColorToNumber: (num: string) => number;