/**
 * Triple Exponential Moving Average (T3)
 *
 * T3 is a triple-smoothed moving average developed by Tim Tillson that reduces lag
 * and smoothing compared to traditional EMAs while maintaining responsiveness to price changes.
 *
 * @param source - Input data array
 * @param period - Smoothing period (default: 5)
 * @param volumeFactor - Volume factor for smoothing (default: 0.7)
 * @returns T3 values
 */
/**
 * Triple Exponential Moving Average (T3)
 *
 * Implemented following TA‑Lib's algorithm (see TA_T3 C implementation).
 * This inlines the nested EMA seeding (e1..e6) and performs a single-pass
 * update, which is significantly faster than calling `ema()` six times.
 *
 * Notes:
 * - Lookback = 6 * (period - 1)
 * - For inputs containing NaNs we propagate NaN outputs where we cannot
 *   compute valid seeds or updates.
 */
export declare function t3(source: ArrayLike<number>, period: number, volumeFactor: number): Float64Array;