import { Equation, Step } from './types.js';
/**
 * Represents basic functions for a differential equation.
 */
export declare class DifferentialEquationBase {
    private readonly dnx;
    /**
     * The highest derivative order of this differential equation
     */
    private readonly order;
    /**
     * Stores information for this differential equation
     */
    private readonly data;
    /**
     * Current state vector used to evaluate the derivative equation
     */
    private state;
    /**
     * Create a new differential equation.
     * @param dnx The formula for `d(n)x/dt(n)` where `n` is the highest order
     * @param x0 Initial conditions for all `n-1` derivative orders ordered by `x`, `dx/dt`, `d2x/dt2`, ..., `d(n-1)x/dt(n-1)`
     */
    constructor(dnx: Equation, ...x0: number[]);
    /**
     * Calculate `x` and all its derivatives after a timestep `dt`.
     * @param dt The timestep
     */
    step(dt: number): void;
    /**
     * Set the global state vector used by `d(n)x/dt(n)` in the next timestep, such as `x`, `dx/dt`, ..., `d(n-1)x/dt(n-1)`.
     * @param x State values used in `d(n)x/dt(n)`
     */
    setState(...x: number[]): void;
    /**
     * Get the current state vector for this equation at time `t`, ordered from lowest derivative to highest order, excluding order `n`.
     * @returns `x`, `dx/dt`, ..., `d(n-1)x/dt(n-1)`
     */
    getState(): number[];
    /**
     * Get the current time of the solution.
     * @returns The current time `t`
     */
    getTime(): number;
    /**
     * Get all data for this differential equation.
     * @returns An array containing each timestamp and all derivatives evaluated at that timestamp
     */
    getData(): Step[];
}