/**
 * Dynamic time warping between two feature sequences (or a precomputed
 * cost matrix).
 *
 * @param {Array<Array<number>|Float32Array|Float64Array>|null} X
 *   Feature matrix, shape (d, N) — rows are features, columns are frames.
 *   Pass null when supplying `options.C`.
 * @param {Array<Array<number>|Float32Array|Float64Array>|null} Y
 *   Feature matrix, shape (d, M). Pass null when supplying `options.C`.
 * @param {Object} [options]
 * @param {Array<Array<number>>} [options.C=null] - precomputed cost matrix (N, M).
 *   Mutually exclusive with X/Y.
 * @param {string} [options.metric='euclidean']
 * @param {Array<Array<number>>} [options.stepSizesSigma=null] - custom steps,
 *   APPENDED to the defaults.
 * @param {Array<number>} [options.weightsAdd=null] - additive step weights.
 * @param {Array<number>} [options.weightsMul=null] - multiplicative step weights.
 * @param {boolean} [options.subseq=false] - subsequence DTW.
 * @param {boolean} [options.backtrack=true] - also return the warping path.
 * @param {boolean} [options.globalConstraints=false] - Sakoe-Chiba band.
 * @param {number} [options.bandRad=0.25] - band radius as a fraction of min(N, M).
 * @param {boolean} [options.returnSteps=false] - also return the step matrix.
 * @returns {{D: Float64Array[], wp?: number[][], steps?: Int32Array[]}}
 *   `D` is the (N, M) accumulated cost matrix (`D[N-1][M-1]` is the total
 *   alignment cost). `wp` (when backtrack) is the warping path from the end
 *   of the alignment down to its start.
 */
export function dtw(X?: Array<Array<number> | Float32Array | Float64Array> | null, Y?: Array<Array<number> | Float32Array | Float64Array> | null, options?: {
    C?: Array<Array<number>>;
    metric?: string;
    stepSizesSigma?: Array<Array<number>>;
    weightsAdd?: Array<number>;
    weightsMul?: Array<number>;
    subseq?: boolean;
    backtrack?: boolean;
    globalConstraints?: boolean;
    bandRad?: number;
    returnSteps?: boolean;
}): {
    D: Float64Array[];
    wp?: number[][];
    steps?: Int32Array[];
};
/**
 * Backtrack a warping path from a recorded step matrix.
 *
 * @param {Int32Array[]|Array<Array<number>>} steps - step matrix from `dtw`
 *   (`returnSteps: true`).
 * @param {Object} [options]
 * @param {Array<Array<number>>} [options.stepSizesSigma=null] - the SAME
 *   custom steps passed to `dtw` (they are appended to the defaults here
 *   too, so index bookkeeping matches the forward pass).
 * @param {boolean} [options.subseq=false]
 * @param {number|null} [options.start=null] - start column (subseq only).
 * @returns {number[][]} warping path, end-to-start.
 */
export function dtwBacktracking(steps: Int32Array[] | Array<Array<number>>, options?: {
    stepSizesSigma?: Array<Array<number>>;
    subseq?: boolean;
    start?: number | null;
}): number[][];