differential_equations/dde/
numerical_method.rs

1//! Numerical Methods for solving delay differential equations (DDEs).
2
3use crate::{
4    Error, Status,
5    alias::Evals,
6    dde::DDE,
7    traits::{CallBackData, Real, State},
8};
9
10/// DDENumericalMethod Trait for DDE NumericalMethods
11///
12/// DDE NumericalMethods implement this trait to solve delay differential equations.
13/// The `step` function is called iteratively by a solver function (like `solve_dde`)
14/// to advance the solution.
15///
16pub trait DDENumericalMethod<const L: usize, T, V, H, D = String>
17where
18    T: Real,
19    V: State<T>,
20    H: Fn(T) -> V,
21    D: CallBackData,
22{
23    /// Initialize DDENumericalMethod before solving DDE.
24    ///
25    /// # Arguments
26    /// * `dde` - System of DDEs to solve.
27    /// * `t0`  - Initial time.
28    /// * `tf`  - Final time.
29    /// * `y0`  - Initial state at `t0`.
30    /// * `phi` - Initial history function `phi(t)` returning state `V` for `t <= t0`.
31    ///
32    /// # Returns
33    /// * Result<NumEvals, Error<T, V>> - Ok(evals) if initialization is successful, Err otherwise.
34    ///
35    fn init<F>(&mut self, dde: &F, t0: T, tf: T, y0: &V, phi: H) -> Result<Evals, Error<T, V>>
36    where
37        F: DDE<L, T, V, D>;
38
39    /// Perform one integration step for the DDE.
40    ///
41    /// # Arguments
42    /// * `dde`            - System of DDEs to solve.
43    ///
44    /// # Returns
45    /// * Result<NumEvals, Error<T, V>> - Ok(evals) if step is successful, Err otherwise.
46    ///
47    fn step<F>(&mut self, dde: &F) -> Result<Evals, Error<T, V>>
48    where
49        F: DDE<L, T, V, D>;
50
51    // Access fields of the solver
52
53    /// Access time of the current state (end of the last accepted step).
54    fn t(&self) -> T;
55
56    /// Access solution state `y` at the current time `t`.
57    fn y(&self) -> &V;
58
59    /// Access time at the beginning of the last accepted step.
60    fn t_prev(&self) -> T;
61
62    /// Access solution state `y` at the beginning of the last accepted step.
63    fn y_prev(&self) -> &V;
64
65    /// Access the proposed step size `h` for the *next* step attempt.
66    fn h(&self) -> T;
67
68    /// Set the step size `h` for the *next* step attempt.
69    fn set_h(&mut self, h: T);
70
71    /// Get the current status of the solver (Solving, Complete, Error, etc.).
72    fn status(&self) -> &Status<T, V, D>;
73
74    /// Set the status of the solver.
75    fn set_status(&mut self, status: Status<T, V, D>);
76}
differential_equations/dde/numerical_method.rs

differential_equations/dde/
numerical_method.rs
