1 // Copyright (c) 2017-2026, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED: http://github.com/ceed
7
8 // ----------------------------------------------------------------------------
9 // Transform mesh coordinates
10 // ----------------------------------------------------------------------------
transform_mesh_coordinates( dim: usize, mesh_size: usize, mesh_coords: &mut libceed::Vector, ) -> libceed::Result<libceed::Scalar>11 pub(crate) fn transform_mesh_coordinates(
12 dim: usize,
13 mesh_size: usize,
14 mesh_coords: &mut libceed::Vector,
15 ) -> libceed::Result<libceed::Scalar> {
16 // Transform coordinates
17 match dim {
18 1 => {
19 for coord in mesh_coords.view_mut()?.iter_mut() {
20 // map [0,1] to [0,1] varying the mesh density
21 *coord = 0.5
22 + 1.0 / (3.0 as libceed::Scalar).sqrt()
23 * ((2.0 / 3.0) * std::f64::consts::PI as libceed::Scalar * (*coord - 0.5))
24 .sin()
25 }
26 }
27 _ => {
28 let num_nodes = mesh_size / dim;
29 let mut coords = mesh_coords.view_mut()?;
30 for i in 0..num_nodes {
31 // map (x,y) from [0,1]x[0,1] to the quarter annulus with polar
32 // coordinates, (r,phi) in [1,2]x[0,pi/2] with area = 3/4*pi
33 let u = coords[i] + 1.;
34 let v = coords[i + num_nodes] * std::f64::consts::PI / 2.;
35 coords[i] = u * v.cos();
36 coords[i + num_nodes] = u * v.sin();
37 }
38 }
39 }
40
41 // Exact volume of transformed region
42 let exact_volume = match dim {
43 1 => 1.,
44 2 | 3 => 3. / 4. * std::f64::consts::PI,
45 _ => unreachable!(),
46 };
47 Ok(exact_volume)
48 }
49
50 // ----------------------------------------------------------------------------
51