import { ForceIndex as FIIndicator } from 'technicalindicators';
import { OHLC } from '../types';
import { IndicatorInput, Indicator } from './base-indicator';
export interface ForceIndexInput extends IndicatorInput {
    period?: number;
}
/**
 * The force index is a technical indicator that measures the amount of
 * power used to move the price of an asset. The term and its formula were
 * developed by psychologist and trader Alexander Elder and published in his
 * 1993 book Trading for a Living. The force index uses price and volume to
 * determine the amount of strength behind a price move. The index is an
 * oscillator, fluctuating between positive and negative territory. It is
 * unbounded meaning the index can go up or down indefinitely. The force index
 * is used for trend and breakout confirmation, as well as spotting potential
 * turning points by looking for divergences.
 */
export declare class FI implements Indicator {
    indicator: FIIndicator;
    /**
     * @param {OHLC[]} series candles series
     * @param {number} period period for indicator
     */
    constructor(series: OHLC[], period?: number);
    /**
     * Retrieve FI values for instance
     * @return {number[]} values for instance data
     */
    getResults(): number[];
    /**
     * Calculate FI to next tick
     * @param {OHLC} candle new candle to add to series
     * @return {number | undefined} next FI value or undefined if period is
     * greater than actual series length
     */
    next(candle: OHLC): number | undefined;
    /**
     * Create instance from data
     * @param {ForceIndexInput} input input data
     * @return {FI} FI instance
     */
    static generator({ series, period }: ForceIndexInput): FI;
    /**
     * Get FI values from input
     * @param {ForceIndexInput} input input data
     * @return {number[]} FI values
     */
    static calculate({ series, period, }: ForceIndexInput): number[];
}