import type { ReactNode } from "react";
/**
 * The data layer for `Matrix` — axis types + the cross-tab aggregation. Its own
 * module so it unit-tests directly, and so a consumer can drive a KPI off the
 * same `matrixTotals` the grid shows.
 */
export interface MatrixAxisItem {
    key: string;
    label: string;
    /** An identity mark before the label. ROWS ONLY — a column is a period or a
     *  category and has no identity to carry, so `Matrix.Header` ignores this. The
     *  mark is drawn INSIDE `rowLabelWidth`. */
    leading?: ReactNode;
}
/** The inspected cell — host renders its detail (a filtered list) underneath. */
export interface MatrixCellRef {
    row: string;
    col: string;
}
export interface MatrixTotalsResult {
    rowTotals: Map<string, number>;
    colTotals: Map<string, number>;
    grandTotal: number;
    /** The largest single cell — the heat scale's upper bound. */
    max: number;
}
/** How a cell's value becomes ink. See `matrixHeatScale`. */
export type MatrixHeatScale = "linear" | "rank";
export interface MatrixHeatScaleResult {
    /** The alpha this scale paints a cell with. Zero (and below) paints nothing. */
    alpha: (value: number) => number;
    /** The legend's swatches — the SAME alphas, sampled across the painted set. */
    legend: number[];
}
/**
 * Value → ink, and the legend that explains it, from ONE expression.
 *
 * `linear` maps a cell onto the band by its share of the largest cell, which is
 * honest only when the values are spread. `rank` maps a cell by its POSITION
 * among the DISTINCT values painted, so the smallest always lands on `lo`, the
 * largest on `hi`, and equal cells keep equal ink.
 *
 * The legend is SAMPLED from that same function rather than restated, so it can
 * never paint a shade the grid cannot reach.
 */
export declare function matrixHeatScale(values: number[], scale: MatrixHeatScale, band: [number, number]): MatrixHeatScaleResult;
/**
 * Row sums, column sums, grand total, and the max single cell — computed in one
 * pass. The single source of truth for the matrix's totals.
 */
export declare function matrixTotals(rows: MatrixAxisItem[], cols: MatrixAxisItem[], value: (row: string, col: string) => number): MatrixTotalsResult;