Struct UnsplitIntegrator 

pub struct UnsplitIntegrator {
    pub rk_stages: usize,
    pub g: f64,
    pub domain: Domain,
    /* private fields */
}

Method-of-lines Runge-Kutta integrator for the full 6D Vlasov PDE.

Unlike split integrators (Strang, Yoshida), this evaluates the complete RHS = -v . grad_x f + g . grad_v f at each stage, re-solving Poisson for the intermediate state. This avoids splitting error but is more expensive per timestep and subject to CFL constraints.

Fields

rk_stages: usize

Number of Runge-Kutta stages (2, 3, or 4).

g: f64

Gravitational constant G.

domain: Domain

Computational domain (grid spacings, extents, BCs).

Implementations

impl UnsplitIntegrator

pub fn new(rk_stages: usize, g: f64, domain: Domain) -> Self

Create a new unsplit integrator.

Panics

Panics if rk_stages is not 2, 3, or 4.

Trait Implementations

impl TimeIntegrator for UnsplitIntegrator

fn advance( &mut self, repr: &mut dyn PhaseSpaceRepr, solver: &dyn PoissonSolver, advector: &dyn Advector, dt: f64, ) -> Result<StepProducts, CausticError>

Advance the distribution by one timestep dt using the configured RK scheme.

Extracts the current state as a flat 6D snapshot, evaluates the Vlasov RHS at each RK stage (re-solving Poisson each time), and loads the result back.

fn max_dt(&self, repr: &dyn PhaseSpaceRepr, cfl_factor: f64) -> f64

CFL condition for the unsplit integrator.

dt <= cfl_factor * min(min_dx / v_max, min_dv / g_max)

• v_max is the maximum velocity from the domain velocity extent.
• g_max is estimated from the dynamical time: g_max ~ sqrt(G * rho_max) * L_box, or equivalently the inverse dynamical time 1/sqrt(G * rho_max).

fn set_progress(&mut self, progress: Arc<StepProgress>)

Attach a progress reporter for intra-step TUI updates.

fn last_step_timings(&self) -> Option<&StepTimings>

Return timing breakdown from the most recent advance() call. Default returns None; instrumented integrators override this.

fn suggested_dt(&self) -> Option<f64>

Return a suggested Δt from the adaptive controller (if any). Default returns None; adaptive integrators override this.