Struct DormandPrince45 

pub struct DormandPrince45 {
    pub atol: f64,
    pub rtol: f64,
    pub dt_min: f64,
    pub dt_max: f64,
}

Dormand-Prince RK45 adaptive integrator with FSAL (First Same As Last).

This is the method underlying MATLAB’s ode45 and SciPy’s RK45. The 5th-order solution is used to advance the state; the 4th-order solution is used only for error estimation. The FSAL property means only 5 new function evaluations per accepted step (the last stage of step n equals the first stage of step n+1).

Fields

atol: f64

Absolute error tolerance.

rtol: f64

Relative error tolerance.

dt_min: f64

Minimum allowed step size.

dt_max: f64

Maximum allowed step size.

Implementations

impl DormandPrince45

pub fn new(atol: f64, rtol: f64, dt_min: f64, dt_max: f64) -> Self

Construct with specified tolerances and step bounds.

pub fn default_tolerances() -> Self

Construct with default tolerances (1e-6 / 1e-6).

pub fn step<F>( &self, s: &OdeState, h: f64, f: &F, k1_in: Option<&Vec<f64>>, ) -> (OdeState, f64, Vec<f64>)

where F: Fn(f64, &[f64]) -> Vec<f64>,

Perform one FSAL Dormand-Prince step from state s with step h.

Returns (new_state, error_rms, k7) where k7 is the last stage (reusable as the first stage of the next step via FSAL).

pub fn integrate<F>( &self, s0: &OdeState, t_end: f64, dt_init: f64, f: &F, ) -> OdeSolution

where F: Fn(f64, &[f64]) -> Vec<f64>,

Integrate from s0 to t_end with adaptive step control.

Returns an OdeSolution containing all accepted states.