import type { NamedReactionPath, NebImage, PathMetricOptions, ReactionCoordOptions, ReactionPath, ReactionPathInput } from './index';
export declare const path_energy_unit: (path: ReactionPath | NebImage[]) => string;
export declare function normalize_paths(input: ReactionPathInput): NamedReactionPath[];
export declare function assert_path(path: ReactionPath | NebImage[], context?: string): NebImage[];
export declare function reaction_coordinate(path: ReactionPath | NebImage[], options?: ReactionCoordOptions): number[];
export type BarrierAnalysis = {
    initial_energy: number;
    final_energy: number;
    ts_image_idx: number;
    ts_energy: number;
    ts_coordinate: number;
    forward_barrier: number;
    reverse_barrier: number;
    reaction_energy: number;
    energy_unit: string;
};
export declare function analyze_barrier(path: ReactionPath | NebImage[], options?: ReactionCoordOptions, coords?: readonly number[]): BarrierAnalysis;
export declare function projected_force_slopes(path: ReactionPath | NebImage[], options?: PathMetricOptions): number[] | null;
export declare function natural_cubic_slopes(xs: readonly number[], ys: readonly number[]): number[];
export type PathSpline = {
    method: `force-hermite` | `natural-cubic`;
    coords: number[];
    energies: number[];
    knot_slopes: number[];
    fitted_max: {
        coord: number;
        energy: number;
        between_images: [number, number];
    };
    highest_image: {
        idx: number;
        coord: number;
        energy: number;
    };
    saddle_at_image: boolean;
};
export declare function fit_path_spline(coords: readonly number[], energies: readonly number[], options?: {
    slopes?: readonly number[];
    n_samples?: number;
}): PathSpline;
export type PathSplineOptions = ReactionCoordOptions & {
    n_samples?: number;
    ignore_forces?: boolean;
};
export declare function path_spline(path: ReactionPath | NebImage[], options?: PathSplineOptions, coords?: readonly number[]): PathSpline;
export type PathProfile = {
    coords: number[];
    energies: number[];
    analysis: BarrierAnalysis;
    spline: PathSpline;
};
export declare function path_profile(path: ReactionPath | NebImage[], options?: PathSplineOptions): PathProfile;
export declare function nearest_image_idx(coords: readonly number[], coord: number): number;