export type ChartExportFormat = `png` | `svg` | `csv`;
export declare function export_chart_image(svg_element: SVGElement | null, base_filename: string, format: `svg` | `png`): void;
export type CsvCell = string | number | null | undefined;
export declare const to_csv: (header: readonly string[], rows: readonly CsvCell[][]) => string;
export interface CsvSeries {
    label?: string;
    x: readonly number[];
    y: readonly number[];
    extras?: Record<string, readonly (number | null | undefined)[] | undefined>;
}
export declare function series_to_csv_rows(series: readonly CsvSeries[]): {
    header: string[];
    rows: CsvCell[][];
};
export declare const export_filename: (...parts: (string | undefined)[]) => string;
export declare const create_chart_exporter: (frame: {
    svg_element: SVGElement | null;
    title_config?: {
        text?: string;
    } | null;
    axes: {
        x: {
            label?: string;
        };
        y: {
            label?: string;
        };
    };
}, csv: () => {
    header: readonly string[];
    rows: CsvCell[][];
}) => (format: ChartExportFormat) => void;