export declare const CHART_MARGIN: {
    readonly top: 12;
    readonly right: 16;
    readonly bottom: 32;
    readonly left: 44;
};
export declare function niceTicks(min: number, max: number, target?: number): number[];
export declare function fixedTicks(min: number, max: number, target?: number): number[];
export declare function scaleLinear(v: number, d0: number, d1: number, r0: number, r1: number): number;
/** Value-axis scale type. `log` requires strictly positive values. */
export type ChartScale = "linear" | "log";
/** Lowest strictly-positive value among the args; floor for a log domain. */
export declare function smallestPositive(...vals: number[]): number;
/** Power-of-ten ("nice") ticks spanning `[min, max]` for a log axis. */
export declare function logTicks(min: number, max: number): number[];
export declare function fixedLogTicks(min: number, max: number): number[];
export declare function validLinearDomain(domain: [number, number] | undefined): [number, number] | null;
export declare function validLogDomain(domain: [number, number] | undefined): [number, number] | null;
export declare function clampFraction(value: number): number;
export declare function formatTick(v: number): string;
export declare function isNumeric(x: number | string): x is number;
export declare function buildLinearPath(pts: {
    x: number;
    y: number;
}[]): string;
export declare function buildSmoothPath(pts: {
    x: number;
    y: number;
}[]): string;
/**
 * Maximal runs of consecutive line segments sharing the same kind; `start` /
 * `end` are inclusive point indices. A segment between two consecutive points
 * is a forecast (dashed) segment when EITHER endpoint is a forecast datum, so
 * the actual→forecast transition stays connected.
 */
export type ForecastRun = {
    start: number;
    end: number;
    forecast: boolean;
};
export declare function forecastRuns(flags: boolean[]): ForecastRun[];
/** `true` si le ton catégoriel est clair (texte sombre requis pour le contraste). */
export declare function isLightTone(tone: string): boolean;
/** Couleur de texte (token) lisible sur un fond catégoriel donné. */
export declare function labelColorForTone(tone: string): string;
/**
 * Semantic tone for an analytical overlay (reference line / band / goal).
 * Maps to the feedback token family — these are *markers*, not categorical
 * series, so they reuse the success/warning/error/info semantics. `neutral`
 * (the default) uses the strong border / secondary text tokens.
 */
export type ChartOverlayTone = "neutral" | "success" | "warning" | "error" | "info";
export type ChartReferenceLine = {
    value: number;
    label?: string;
    tone?: ChartOverlayTone;
    axis?: "x" | "y";
};
export type ChartBand = {
    from: number;
    to: number;
    label?: string;
    tone?: ChartOverlayTone;
};
export type ChartGoalLine = {
    value: number;
    label?: string;
};
/** Tone-suffixed class name for an overlay element (defaults to `neutral`). */
export declare function overlayToneClass(prefix: string, tone: ChartOverlayTone | undefined): string;
/**
 * Least-squares linear regression over finite points. Returns the line in DATA
 * space (`y = slope·x + intercept`) plus the x-range it was fit on, or `null`
 * when fewer than two finite points exist or the x-values are degenerate.
 */
export declare function linearRegression(pts: ReadonlyArray<{
    x: number;
    y: number;
}>): {
    slope: number;
    intercept: number;
    minX: number;
    maxX: number;
} | null;
/**
 * Extends a value-axis `[min, max]` so finite overlay values stay inside the
 * plot. Reference lines on the value axis (default `y`), band bounds, the goal
 * value and finite error-bar extents are all folded in. Non-finite values are
 * ignored. Returns the original range untouched when no overlay needs it.
 */
export declare function extendValueDomain(min: number, max: number, overlays: {
    referenceLines?: ReadonlyArray<ChartReferenceLine>;
    referenceAxis?: "x" | "y";
    bands?: ReadonlyArray<ChartBand>;
    goalLine?: ChartGoalLine | null;
    extraValues?: ReadonlyArray<number>;
}): [number, number];
/**
 * Screen-reader descriptions of the active overlays, appended after the data
 * values in the ChartDataList. Empty when no overlay is present.
 */
export declare function overlayDataListItems(overlays: {
    referenceLines?: ReadonlyArray<ChartReferenceLine>;
    bands?: ReadonlyArray<ChartBand>;
    goalLine?: ChartGoalLine | null;
    trend?: {
        slope: number;
        intercept: number;
    } | null;
}): string[];
export declare function chartDataList(label: string, items: string[]): import("vue").VNode<import("vue").RendererNode, import("vue").RendererElement, {
    [key: string]: any;
}> | null;
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