Struct EvenSolout

pub struct EvenSolout<T: Real> { /* private fields */ }

An output handler that provides solution points at evenly spaced time intervals.

Overview

EvenSolout generates output points at strictly uniform time intervals, creating a regular grid of solution points. This is especially useful for visualization, post-processing, or when interfacing with other systems that expect uniformly sampled data.

Unlike DefaultSolout which captures the naturally occurring solver steps (which may have varying time intervals), EvenSolout uses interpolation to evaluate the solution at precise time points separated by a fixed interval.

Example

use differential_equations::prelude::*;
use differential_equations::solout::EvenSolout;
use nalgebra::{Vector2, vector};

// Simple harmonic oscillator
struct HarmonicOscillator;

impl ODE<f64, Vector2<f64>> for HarmonicOscillator {
    fn diff(&self, _t: f64, y: &Vector2<f64>, dydt: &mut Vector2<f64>) {
        // y[0] = position, y[1] = velocity
        dydt[0] = y[1];
        dydt[1] = -y[0];
    }
}

// Create the system and solver
let system = HarmonicOscillator;
let t0 = 0.0;
let tf = 10.0;
let y0 = vector![1.0, 0.0];
let mut solver = DOP853::new().rtol(1e-6).atol(1e-8);

// Generate output points with a fixed interval of 0.1
let mut even_output = EvenSolout::new(0.1, t0, tf);

// Solve with evenly spaced output
let problem = ODEProblem::new(system, t0, tf, y0);
let solution = problem.solout(&mut even_output).solve(&mut solver).unwrap();

// Note: This is equivalent to using the convenience method:
let solution = problem.even(0.1).solve(&mut solver).unwrap();

Output Characteristics

The output will contain points at regular intervals: t₀, t₀+dt, t₀+2dt, …, tₙ. The final point tₙ is guaranteed to be included, even if it doesn’t fall exactly on the regular grid. Any evaluation points that fall outside the integration range are ignored.

Implementations

impl<T: Real> EvenSolout<T>

pub fn new(dt: T, t0: T, tf: T) -> Self

Creates a new EvenSolout instance with the specified time interval.

This output handler will generate solution points at regular intervals of dt starting from t0 and continuing through tf. The points will be aligned with t0 (i.e., t₀, t₀+dt, t₀+2dt, …).

Arguments

• dt - The fixed time interval between output points
• t0 - The initial time of the integration
• tf - The final time of the integration

Returns

• A new EvenSolout instance

Trait Implementations

impl<T, V, D> Solout<T, V, D> for EvenSolout<T>

where T: Real, V: State<T>, D: CallBackData,

fn solout<I>( &mut self, t_curr: T, t_prev: T, y_curr: &V, y_prev: &V, interpolator: &mut I, solution: &mut Solution<T, V, D>, ) -> ControlFlag<T, V, D>

where I: Interpolation<T, V>,

Solout function to choose which points to output during the solving process.