1 // Copyright (c) 2017-2025, 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 // ---------------------------------------------------------------------------- 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 if dim == 1 { 18 for coord in mesh_coords.view_mut()?.iter_mut() { 19 // map [0,1] to [0,1] varying the mesh density 20 *coord = 0.5 21 + 1.0 / (3.0 as libceed::Scalar).sqrt() 22 * ((2.0 / 3.0) * std::f64::consts::PI as libceed::Scalar * (*coord - 0.5)).sin() 23 } 24 } else { 25 let mut coords = mesh_coords.view_mut()?; 26 let num_nodes = mesh_size / dim; 27 for i in 0..num_nodes { 28 // map (x,y) from [0,1]x[0,1] to the quarter annulus with polar 29 // coordinates, (r,phi) in [1,2]x[0,pi/2] with area = 3/4*pi 30 let u = 1.0 + coords[i]; 31 let v = std::f64::consts::PI as libceed::Scalar / 2.0 * coords[i + num_nodes]; 32 coords[i] = u * v.cos(); 33 coords[i + num_nodes] = u * v.sin(); 34 } 35 } 36 37 // Exact volume of transformed region 38 let exact_volume = match dim { 39 1 => 1.0, 40 2 | 3 => 3.0 / 4.0 * std::f64::consts::PI as libceed::Scalar, 41 _ => unreachable!(), 42 }; 43 Ok(exact_volume) 44 } 45 46 // ---------------------------------------------------------------------------- 47