From e957a4fff78a31979a7e75c6f66a2624aace0fd5 Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <flymagnus@gmail.com>
Date: Wed, 29 Jan 2020 20:50:56 +0100
Subject: [PATCH] move integrator to module

---
 src/euler.rs     | 46 ++--------------------------------------------
 src/integrate.rs | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs       |  1 +
 3 files changed, 49 insertions(+), 44 deletions(-)
 create mode 100644 src/integrate.rs

diff --git a/src/euler.rs b/src/euler.rs
index 02e3f05..876a479 100644
--- a/src/euler.rs
+++ b/src/euler.rs
@@ -1,7 +1,8 @@
+use super::integrate::integrate_rk4;
 use super::operators::{SbpOperator, UpwindOperator};
 use super::Grid;
+use ndarray::azip;
 use ndarray::prelude::*;
-use ndarray::{azip, Zip};
 
 pub const GAMMA: f32 = 1.4;
 
@@ -224,49 +225,6 @@ impl Field {
     }
 }
 
-pub(crate) fn integrate_rk4<'a, F: 'a, SBP, RHS, WB>(
-    rhs: RHS,
-    prev: &F,
-    fut: &mut F,
-    dt: f32,
-    grid: &Grid<SBP>,
-    k: &mut [F; 4],
-    mut wb: &mut WB,
-) where
-    F: std::ops::Deref<Target = Array3<f32>> + std::ops::DerefMut<Target = Array3<f32>>,
-    SBP: SbpOperator,
-    RHS: Fn(&mut F, &F, &Grid<SBP>, &mut WB),
-{
-    assert_eq!(prev.shape(), fut.shape());
-
-    for i in 0..4 {
-        // y = y0 + c*kn
-        fut.assign(prev);
-        match i {
-            0 => {}
-            1 | 2 => {
-                fut.scaled_add(1.0 / 2.0 * dt, &k[i - 1]);
-            }
-            3 => {
-                fut.scaled_add(dt, &k[i - 1]);
-            }
-            _ => {
-                unreachable!();
-            }
-        };
-
-        rhs(&mut k[i], &fut, grid, &mut wb);
-    }
-
-    Zip::from(&mut **fut)
-        .and(&**prev)
-        .and(&*k[0])
-        .and(&*k[1])
-        .and(&*k[2])
-        .and(&*k[3])
-        .apply(|y1, &y0, &k1, &k2, &k3, &k4| *y1 = y0 + dt / 6.0 * (k1 + 2.0 * k2 + 2.0 * k3 + k4));
-}
-
 fn pressure(gamma: f32, rho: f32, rhou: f32, rhov: f32, e: f32) -> f32 {
     (gamma - 1.0) * (e - (rhou * rhou + rhov * rhov) / (2.0 * rho))
 }
diff --git a/src/integrate.rs b/src/integrate.rs
new file mode 100644
index 0000000..57f26e4
--- /dev/null
+++ b/src/integrate.rs
@@ -0,0 +1,46 @@
+use super::grid::Grid;
+use super::operators::SbpOperator;
+use ndarray::{Array3, Zip};
+
+pub(crate) fn integrate_rk4<'a, F: 'a, SBP, RHS, WB>(
+    rhs: RHS,
+    prev: &F,
+    fut: &mut F,
+    dt: f32,
+    grid: &Grid<SBP>,
+    k: &mut [F; 4],
+    mut wb: &mut WB,
+) where
+    F: std::ops::Deref<Target = Array3<f32>> + std::ops::DerefMut<Target = Array3<f32>>,
+    SBP: SbpOperator,
+    RHS: Fn(&mut F, &F, &Grid<SBP>, &mut WB),
+{
+    assert_eq!(prev.shape(), fut.shape());
+
+    for i in 0..4 {
+        // y = y0 + c*kn
+        fut.assign(prev);
+        match i {
+            0 => {}
+            1 | 2 => {
+                fut.scaled_add(1.0 / 2.0 * dt, &k[i - 1]);
+            }
+            3 => {
+                fut.scaled_add(dt, &k[i - 1]);
+            }
+            _ => {
+                unreachable!();
+            }
+        };
+
+        rhs(&mut k[i], &fut, grid, &mut wb);
+    }
+
+    Zip::from(&mut **fut)
+        .and(&**prev)
+        .and(&*k[0])
+        .and(&*k[1])
+        .and(&*k[2])
+        .and(&*k[3])
+        .apply(|y1, &y0, &k1, &k2, &k3, &k4| *y1 = y0 + dt / 6.0 * (k1 + 2.0 * k2 + 2.0 * k3 + k4));
+}
diff --git a/src/lib.rs b/src/lib.rs
index 0a0b710..a8c70a0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,6 +2,7 @@ use wasm_bindgen::prelude::*;
 
 pub mod euler;
 mod grid;
+pub(crate) mod integrate;
 mod maxwell;
 pub mod operators;
 pub use crate::maxwell::{Field, WorkBuffers};