import { Candle } from '../types';
/**
 * Computes the Average True Range (ATR) for a series of candles using a simple mean.
 *
 * True Range for each candle (after the first) is:
 *   TR = max(high − low, |high − prev.close|, |low − prev.close|)
 *
 * For the first candle (no previous close), TR = high − low.
 *
 * @param candles - Array of Candle objects. Should contain the context window preceding the zone.
 * @param period  - Number of TR values to average (default: DEFAULT_ATR_PERIOD).
 * @returns The mean TR over the last `period` values, or 0 if the array is empty.
 */
export declare function atr(candles: Candle[], period?: number): number;