/**
 * Sets initial values for summaries.
 *
 * @param {Array} summaries - An array of summary objects.
 * @returns {Object} An object with keys for each summary initialized to empty arrays.
 */
export function initialValues(summaries: any[]): Object;
/**
 * Adds data to summary aggregation arrays.
 *
 * @param {Object} group - The group object to add data to.
 * @param {Object} row - The data row being processed.
 * @param {Array} summaries - An array of summary objects.
 */
export function addToSummaries(group: Object, row: Object, summaries: any[]): void;
/**
 * Groups data by specified keys using a composite string key (Phase 3: replaces JSON.stringify).
 *
 * @param {Array} data - An array of data points.
 * @param {Array} groupByKeys - Keys to group the data by.
 * @param {Array} summaries - An array of summary objects to define aggregation operations.
 * @returns {Object} Grouped data object with aggregation placeholders.
 */
export function groupDataByKeys(data: any[], groupByKeys: any[], summaries: any[]): Object;
/**
 * Fills grouped data with aligned data if specified in configuration.
 *
 * @param {Object} groupedData - The grouped data object.
 * @param {Object} config - Configuration object containing alignment settings.
 * @returns {Array} Aligned data array.
 */
export function fillAlignedData(groupedData: Object, config: Object, fillRowsFunc: any): any[];
export function getAlignGenerator(data: any, config: any): (children: any) => any[];
/**
 * Performs aggregation operations on grouped data.
 *
 * @param {Array} dataArray - An array of grouped data with aggregation arrays.
 * @param {Array} summaries - An array of summary objects with reducer functions.
 * @returns {Array} Aggregated data array with computed summary values.
 */
export function aggregateData(dataArray: any[], summaries: any[]): any[];