Struct RK4Integrator 

pub struct RK4Integrator;

Runge-Kutta 4th order integrator.

Fourth-order accurate, non-symplectic. Excellent for smooth problems but energy may drift in long-term simulations.

Algorithm (classical RK4):

k1_v = a(q_n)
k1_q = v_n

k2_v = a(q_n + h/2 * k1_q)
k2_q = v_n + h/2 * k1_v

k3_v = a(q_n + h/2 * k2_q)
k3_q = v_n + h/2 * k2_v

k4_v = a(q_n + h * k3_q)
k4_q = v_n + h * k3_v

v_{n+1} = v_n + h/6 * (k1_v + 2*k2_v + 2*k3_v + k4_v)
q_{n+1} = q_n + h/6 * (k1_q + 2*k2_q + 2*k3_q + k4_q)

Implementations

impl RK4Integrator

pub const fn new() -> Self

Create a new RK4 integrator.

Trait Implementations

impl Clone for RK4Integrator

fn clone(&self) -> RK4Integrator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RK4Integrator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for RK4Integrator

fn default() -> RK4Integrator

Returns the “default value” for a type.

impl Integrator for RK4Integrator

fn step( &self, state: &mut SimState, force_field: &dyn ForceField, dt: f64, ) -> SimResult<()>

Step the state forward by one timestep.

fn error_order(&self) -> u32

Get the error order of this integrator.

fn is_symplectic(&self) -> bool

Check if integrator is symplectic (preserves phase space volume).