basic_particle/
basic_particle.rs

1//! A complete particle loop with an application-owned Rayon pool.
2//! Semi-implicit Euler -> reflecting walls -> Langevin thermostat is the
3//! explicitly chosen splitting here; it is not a higher-order integrator.
4use physics_in_parallel::prelude::basic::{ReflectBox, ResolvedRng, RngMethod, set_max_threads};
5use physics_in_parallel::prelude::models::*;
6
7fn simulate() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
8    let mut particles = create_template(2, 2)?;
9    particles.set_attribute_vector(ATTR_R, 0, &[0.25, 0.5])?;
10    particles.set_attribute_vector(ATTR_R, 1, &[0.75, 0.5])?;
11    set_mass(&mut particles, 0, 2.0)?;
12    let mut springs = SpringNetwork::new();
13    springs.insert((0, 1), Spring::new(1.0, 0.4, None)?)?;
14    let boundary = ReflectBox::new(&[0.0, 0.0], &[1.0, 1.0])?;
15    let mut thermostat = LangevinThermostat::new(
16        0.01,
17        0.1,
18        ResolvedRng::new(42, RngMethod::IndexedSplitMix64),
19        ParticleSelection::AliveOnly,
20    )?;
21    let mut integrator = SemiImplicitEuler;
22    for step in 0..20 {
23        // Force modules accumulate acceleration; each step starts from zero.
24        particles.attribute_mut::<f64>(ATTR_A)?.fill(0.0);
25        springs.apply(&mut particles, ParticleSelection::AliveOnly)?;
26        integrator.apply(&mut particles, 0.01)?;
27        boundary.apply_to_particles(&mut particles)?;
28        thermostat.apply(&mut particles, 0.01)?;
29        if (step + 1) % 10 == 0 {
30            let summary = kinetic_summary(&particles, ParticleSelection::AliveOnly)?;
31            println!(
32                "step {}: KE={}, temperature={}",
33                step + 1,
34                summary.energy,
35                summary.temperature
36            );
37        }
38    }
39    Ok(())
40}
41fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
42    let pool = rayon::ThreadPoolBuilder::new().num_threads(4).build()?;
43    set_max_threads(Some(4))?;
44    pool.install(simulate)
45}
basic_particle/basic_particle.rs

basic_particle/
basic_particle.rs
