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Add D2 operator and heat equation

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Magnus Ulimoen
2020-09-18 17:57:57 +02:00
parent 0fc9ec64ec
commit b80ca3f5e8
5 changed files with 120 additions and 4 deletions
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6
sbp/src/operators.rs
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@@ -17,6 +17,12 @@ pub trait SbpOperator1d: Send + Sync {
fn h_matrix(&self, n: usize) -> sprs::CsMat<Float>;
}
pub trait SbpOperator1d2: SbpOperator1d {
fn diff2(&self, prev: ArrayView1<Float>, fut: ArrayViewMut1<Float>);
/// Lacks a scaling of 1/h^2
fn d1(&self) -> &[Float];
}
pub trait SbpOperator2d: Send + Sync {
fn diffxi(&self, prev: ArrayView2<Float>, fut: ArrayViewMut2<Float>);
fn diffeta(&self, prev: ArrayView2<Float>, fut: ArrayViewMut2<Float>);

38
sbp/src/operators/traditional4.rs
View File

@@ -16,10 +16,22 @@ impl SBP4 {
];
#[rustfmt::skip]
const BLOCK: &'static [&'static [Float]] = &[
&[-1.41176470588235e+00, 1.73529411764706e+00, -2.35294117647059e-01, -8.82352941176471e-02],
&[-5.00000000000000e-01, 0.00000000000000e+00, 5.00000000000000e-01],
&[9.30232558139535e-02, -6.86046511627907e-01, 0.00000000000000e+00, 6.86046511627907e-01, -9.30232558139535e-02],
&[3.06122448979592e-02, 0.00000000000000e+00, -6.02040816326531e-01, 0.00000000000000e+00, 6.53061224489796e-01, -8.16326530612245e-02],
&[-24.0/17.0, 59.0/34.0, -4.0/17.0, -3.0/34.0],
&[-1.0/2.0, 0.0, 1.0/2.0],
&[4.0/43.0, -59.0/86.0, 0.0, 59.0/86.0, -4.0/43.0],
&[3.0/98.0, 0.0, -59.0/98.0, 0.0, 32.0/49.0, -4.0/49.0]
];
#[rustfmt::skip]
const D2DIAG: &'static [Float] = &[
-1.0 / 12.0, 4.0 / 3.0, -5.0 / 2.0, 4.0 / 3.0, -1.0 / 12.0
];
#[rustfmt::skip]
const D2BLOCK: &'static [&'static [Float]] = &[
&[2.0, -5.0, 4.0, -1.0],
&[1.0, -2.0, 1.0],
&[-4.0/43.0, 59.0/43.0, -110.0/43.0, 59.0/43.0, -4.0/43.0],
&[-1.0/49.0, 0.0, 59.0/49.0, -118.0/49.0, 64.0/49.0, -4.0/49.0]
];
}
@@ -81,6 +93,24 @@ impl<SBP: SbpOperator1d> SbpOperator2d for (&SBP, &SBP4) {
}
}
impl super::SbpOperator1d2 for SBP4 {
fn diff2(&self, prev: ArrayView1<Float>, mut fut: ArrayViewMut1<Float>) {
super::diff_op_1d(
Self::D2BLOCK,
Self::D2DIAG,
super::Symmetry::Symmetric,
super::OperatorType::Normal,
prev,
fut.view_mut(),
);
let hi = (prev.len() - 1) as Float;
fut.map_inplace(|x| *x *= hi)
}
fn d1(&self) -> &[Float] {
&[-88.0 / 17.0, 144.0 / 17.0, -72.0 / 17.0, 16.0 / 17.0]
}
}
#[test]
fn test_trad4() {
use super::testing::*;