io/
io.rs

1use itertools::izip;
2use ndelement::{ciarlet::CiarletElement, map::IdentityMap, types::ReferenceCellType};
3use ndgrid::traits::{
4    Builder, Entity, GmshExport, GmshImport, Grid, RONExport, RONImport, Topology,
5};
6use ndgrid::{SingleElementGrid, SingleElementGridBuilder, shapes};
7
8/// Grid I/O
9///
10/// Demonstration of importing and exporting a grid in serial
11///
12/// Parallel I/O is demonstrated in the example `parallel_io.rs`
13fn main() {
14    // Create a grid using the shapes module: unit_cube_boundary will mesh the surface of a cube
15    let g = shapes::unit_cube_boundary::<f64>(4, 5, 4, ReferenceCellType::Triangle);
16
17    // If the serde option is used, the raw grid data can be exported in RON format
18    g.export_as_ron("_unit_cube_boundary.ron");
19
20    // A grid can be re-imported from raw RON data
21    let g2 = SingleElementGrid::<f64, CiarletElement<f64, IdentityMap>>::import_from_ron(
22        "_unit_cube_boundary.ron",
23    );
24
25    // Print the first 5 cells of each grid
26    println!("The first 5 cells of the grids");
27    for (cell, cell2) in izip!(
28        g.entity_iter(ReferenceCellType::Triangle),
29        g2.entity_iter(ReferenceCellType::Triangle)
30    )
31    .take(5)
32    {
33        println!(
34            "{:?} {:?}",
35            cell.topology()
36                .sub_entity_iter(ReferenceCellType::Point)
37                .collect::<Vec<_>>(),
38            cell2
39                .topology()
40                .sub_entity_iter(ReferenceCellType::Point)
41                .collect::<Vec<_>>(),
42        );
43    }
44
45    println!();
46
47    // Alternatively, grids can be exported and imported to/from Gmsh files
48
49    // Export the grid as a Gmsh .msh file
50    g.export_as_gmsh("_unit_cube_boundary.msh");
51
52    // To import from a Gmsh .msh file, a builder is used
53    let mut b = SingleElementGridBuilder::<f64>::new(3, (ReferenceCellType::Triangle, 1));
54    b.import_from_gmsh("_unit_cube_boundary.msh");
55    let g3 = b.create_grid();
56
57    // Print the first 5 cells of each grid
58    println!("The first 5 cells of the grids");
59    for (cell, cell3) in izip!(
60        g.entity_iter(ReferenceCellType::Triangle),
61        g3.entity_iter(ReferenceCellType::Triangle)
62    )
63    .take(5)
64    {
65        println!(
66            "{:?} {:?}",
67            cell.topology()
68                .sub_entity_iter(ReferenceCellType::Point)
69                .collect::<Vec<_>>(),
70            cell3
71                .topology()
72                .sub_entity_iter(ReferenceCellType::Point)
73                .collect::<Vec<_>>(),
74        );
75    }
76}
io/io.rs

io/
io.rs
