diffurch 0.0.3

Numerical solver for ordinary and delay differential equations
Documentation 
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#![allow(incomplete_features)]
#![feature(generic_const_exprs)]

use diffurch::{equation, event, state_fn, event_mut, rk, Filter, Loc, Solver};

fn main() {
    let k = 0.90;
    let g = 9.8;
    let eq = equation!(|[_x, dx]| [dx, -g]).max_delay(f64::INFINITY);

    let ic = [1., -0.01];
    let range = 0. ..8.58;

    let mut points = Vec::new();
    let mut points_continuous = Vec::new();

    Solver::new().rk(&rk::RK98)
        .stepsize(0.05)
        .on_step(event!(|t, [x, _dx]| (t, x)).to_vec(&mut points).to_std())
        .on_step(
            event!(|t, [x, _dx]| (t, x))
                .to_vec(&mut points_continuous)
                .separated_by(0.01)
                .subdivide(21),
        )
        .on(
            Loc::new(state_fn!(|[x, _dx]| x)).while_neg().bisection(),
            event_mut!(|t, [x, dx]| {
                *x = 0.;
                *dx = k * dx.abs();
                *t
            })
            .to_std(),
        )
        .run(eq, ic, range);

    let mut axis = pgfplots::axis::Axis::new();
    for (color, coords) in [("red", points), ("blue", points_continuous)] {
        let mut plot = pgfplots::axis::plot::Plot2D::new();
        plot.coordinates = coords.into_iter().map(|p| p.into()).collect();
        plot.add_key(pgfplots::axis::plot::PlotKey::Custom(color.to_string()));
        axis.plots.push(plot);
    }
    pgfplots::Picture::from(axis)
        .show_pdf(pgfplots::Engine::PdfLatex)
        .unwrap();
}