/**
 * Kaufman Adaptive Moving Average (KAMA).
 * Adapts smoothing based on the efficiency ratio (market noise vs direction).
 * This implementation supports NaN-aware and dense fast-paths; when NaNs are
 * present the compacting + mapping strategy is used, otherwise an O(n)
 * incremental volatility approach is used for speed.
 * @param source Input series
 * @param period Efficiency smoothing lookback (must be > 0)
 * @param fastPeriod Fast smoothing period (default: 2)
 * @param slowPeriod Slow smoothing period (default: 30)
 * @param skipna Whether to ignore NaNs (default: true)
 * @returns Float64Array of KAMA values (NaN where undefined)
 */
export declare function kama(source: ArrayLike<number>, period: number, fastPeriod?: number, slowPeriod?: number, skipna?: boolean): Float64Array;