/**
 * Commodity Channel Index (CCI).
 * Computes the typical price (TP) and compares to a moving average and
 * mean absolute deviation (MAD) scaled by 0.015. Positions before the
 * full lookback or with invalid inputs are NaN.
 * Performance: O(n*p) due to MAD recomputation per window.
 * @param high High price series
 * @param low Low price series
 * @param close Close price series
 * @param period Lookback period (must be > 0)
 * @returns Float64Array of CCI values (NaN where undefined)
 */
export declare function cci(high: ArrayLike<number>, low: ArrayLike<number>, close: ArrayLike<number>, period: number): Float64Array;