Move integrate to separate crate

heat-equation/Cargo.toml

@@ -10,6 +10,7 @@ sbp = { path = "../sbp", features = ["sparse"] }
 ndarray = "0.14.0"
 plotters = { version = "0.3.0", default-features = false, features = ["bitmap_gif", "bitmap_backend", "line_series"] }
 sprs = { version = "0.10.0", default-features = false }
+integrate = { path = "../utils/integrate" }
 
 [dev-dependencies]
 arpack = { git = "https://github.com/mulimoen/arpack-rs", branch = "main" }

heat-equation/src/main.rs

@@ -1,11 +1,24 @@
+use integrate::{integrate, Rk4};
 use ndarray::{Array1, ArrayView1};
 use plotters::prelude::*;
 use sbp::{
-    integrate::{integrate, Rk4},
     operators::{SbpOperator1d, SbpOperator1d2, SBP4},
     Float,
 };
 
+struct Field(Array1<Float>);
+
+impl integrate::Integrable for Field {
+    type State = Array1<Float>;
+    type Diff = Array1<Float>;
+    fn assign(s: &mut Self::State, o: &Self::State) {
+        s.assign(o)
+    }
+    fn scaled_add(s: &mut Self::State, o: &Self::Diff, scale: Float) {
+        s.scaled_add(scale, o)
+    }
+}
+
 fn main() {
     let nx: usize = 101;
     let x = Array1::from_shape_fn((nx,), |i| i as Float / (nx - 1) as Float);
@@ -76,7 +89,7 @@ fn dual_dirichlet(v: ArrayView1<Float>, v0: Float, vn: Float) {
                 .unwrap();
             drawing_area.present().unwrap();
         }
-        integrate::<Rk4, _, _, _>(rhs, &v1, &mut v2, &mut 0.0, dt, &mut k);
+        integrate::<Rk4, Field, _>(rhs, &v1, &mut v2, &mut 0.0, dt, &mut k);
         std::mem::swap(&mut v1, &mut v2);
     }
 }
@@ -143,7 +156,7 @@ fn neumann_dirichlet(v: ArrayView1<Float>, v0: Float, vn: Float) {
                 .unwrap();
             drawing_area.present().unwrap();
         }
-        integrate::<Rk4, _, _, _>(rhs, &v1, &mut v2, &mut 0.0, dt, &mut k);
+        integrate::<Rk4, Field, _>(rhs, &v1, &mut v2, &mut 0.0, dt, &mut k);
         std::mem::swap(&mut v1, &mut v2);
     }
 }
@@ -231,7 +244,7 @@ fn dual_dirichlet_sparse(v: ArrayView1<Float>, v0: Float, vn: Float) {
                 .unwrap();
             drawing_area.present().unwrap();
         }
-        integrate::<Rk4, _, _, _>(rhs, &v1, &mut v2, &mut 0.0, dt, &mut k);
+        integrate::<Rk4, Field, _>(rhs, &v1, &mut v2, &mut 0.0, dt, &mut k);
         std::mem::swap(&mut v1, &mut v2);
     }
 }