Finished dopri5, interpolation, and callbacks

src/integrator/mod.rs

@@ -3,12 +3,18 @@ use nalgebra::SVector;
 use super::ode::ODE;
 
 pub mod dormand_prince;
-pub mod rosenbrock;
+// pub mod rosenbrock;
 
 /// Integrator Trait
 pub trait Integrator<const D: usize> {
+    const ORDER: usize;
     const STAGES: usize;
-    fn step(&mut self, ode: &ODE<D>, h: f64) -> (SVector<f64,D>, Option<f64>);
+    const ADAPTIVE: bool;
+    const DENSE: bool;
+    /// Returns a new y value, then possibly an error value, and possibly a dense output
+    /// coefficient set
+    fn step(&self, ode: &ODE<D>, h: f64) -> (SVector<f64,D>, Option<f64>, Option<Vec<SVector<f64, D>>>);
+    fn interpolate(&self, t_start: f64, t_end: f64, dense: &Vec<SVector<f64,D>>, t: f64) -> SVector<f64,D>;
 }
 
 
@@ -27,13 +33,13 @@ mod tests {
         let y0 = Vector3::new(1.0, 1.0, 1.0);
         let mut ode = ODE::new(&derivative, 0.0, 4.0, y0);
 
-        let mut dp45 = DormandPrince45::new(1e-12_f64, 1e-4_f64);
+        let dp45 = DormandPrince45::new(1e-12_f64, 1e-4_f64);
 
         // Test that y'(t) = y(t) solves to y(t) = e^t for rkf54
         // and also that the error seems reasonable
-        let step = 0.0005;
+        let step = 0.001;
         while ode.t < ode.t_end {
-            let (new_y, err) = dp45.step(&ode, step);
+            let (new_y, err, _) = dp45.step(&ode, step);
             ode.y = new_y;
             ode.t += step;
             assert_relative_eq!(ode.y[0], ode.t.exp(), max_relative=0.01);