gemlab 2.0.0

use super::{Cell, Mesh, Point};
use crate::shapes::GeoKind;

/// Holds samples of meshes
pub struct Samples;

impl Samples {
    /// Returns a mesh with every kind of Lin cell
    ///
    /// **WARNING:** This is not a valid FEM mesh because the cells are not compatible.
    /// We use this function to generate figures for the documentation only.
    ///
    /// ![lin_cells](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_draw_cells_and_points_work_1_lin.svg)
    #[rustfmt::skip]
    pub fn lin_cells() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] }, // 0
                Point { id: 1, marker: 0, coords: vec![1.2, 1.2] }, // 1

                Point { id: 2, marker: 0, coords: vec![1.4+0.0, 0.0] }, // 0
                Point { id: 3, marker: 0, coords: vec![1.4+1.2, 1.2] }, // 1
                Point { id: 4, marker: 0, coords: vec![1.4+0.8, 0.4] }, // 2

                Point { id: 5, marker: 0, coords: vec![2.8+0.0, 0.0] }, // 0
                Point { id: 6, marker: 0, coords: vec![2.8+1.2, 1.2] }, // 1
                Point { id: 7, marker: 0, coords: vec![2.8+0.4, 0.2] }, // 2
                Point { id: 8, marker: 0, coords: vec![2.8+0.8, 0.8] }, // 3

                Point { id:  9, marker: 0, coords: vec![4.2+0.0, 0.0] }, // 0
                Point { id: 10, marker: 0, coords: vec![4.2+1.2, 1.2] }, // 1
                Point { id: 11, marker: 0, coords: vec![4.2+0.6, 0.6] }, // 2
                Point { id: 12, marker: 0, coords: vec![4.2+0.3, 0.2] }, // 3
                Point { id: 13, marker: 0, coords: vec![4.2+0.9, 1.0] }, // 4
            ],
            cells: vec![
                Cell { id: 0, marker: 2, kind: GeoKind::Lin2, points: vec![0, 1] },
                Cell { id: 1, marker: 3, kind: GeoKind::Lin3, points: vec![2, 3, 4] },
                Cell { id: 2, marker: 4, kind: GeoKind::Lin4, points: vec![5, 6, 7, 8] },
                Cell { id: 3, marker: 5, kind: GeoKind::Lin5, points: vec![9, 10, 11, 12, 13] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with every kind of Lin cell in 2D
    ///
    /// **WARNING:** This is not a valid FEM mesh because the cells are not compatible.
    /// We use this function to generate figures for the documentation only.
    ///
    /// ![lin_cells_3d](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_draw_cells_and_points_work_1_lin_3d.svg)
    #[rustfmt::skip]
    pub fn lin_cells_3d() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0, 0.0] }, // 0
                Point { id: 1, marker: 0, coords: vec![1.2, 1.2, 1.2] }, // 1

                Point { id: 2, marker: 0, coords: vec![1.4+0.0, 0.0, 0.0] }, // 0
                Point { id: 3, marker: 0, coords: vec![1.4+1.2, 1.2, 1.2] }, // 1
                Point { id: 4, marker: 0, coords: vec![1.4+0.3, 0.6, 0.6] }, // 2

                Point { id: 5, marker: 0, coords: vec![2.8+0.0, 0.0, 0.0] }, // 0
                Point { id: 6, marker: 0, coords: vec![2.8+1.2, 1.2, 1.2] }, // 1
                Point { id: 7, marker: 0, coords: vec![2.8+0.3, 0.4, 0.4] }, // 2
                Point { id: 8, marker: 0, coords: vec![2.8+0.6, 0.8, 0.8] }, // 3

                Point { id:  9, marker: 0, coords: vec![4.2+0.0, 0.0, 0.0] }, // 0
                Point { id: 10, marker: 0, coords: vec![4.2+1.2, 1.2, 1.2] }, // 1
                Point { id: 11, marker: 0, coords: vec![4.2+0.3, 0.6, 0.6] }, // 2
                Point { id: 12, marker: 0, coords: vec![4.2+0.0, 0.3, 0.3] }, // 3
                Point { id: 13, marker: 0, coords: vec![4.2+0.6, 0.9, 0.9] }, // 4
            ],
            cells: vec![
                Cell { id: 0, marker: 2, kind: GeoKind::Lin2, points: vec![0, 1] },
                Cell { id: 1, marker: 3, kind: GeoKind::Lin3, points: vec![2, 3, 4] },
                Cell { id: 2, marker: 4, kind: GeoKind::Lin4, points: vec![5, 6, 7, 8] },
                Cell { id: 3, marker: 5, kind: GeoKind::Lin5, points: vec![9, 10, 11, 12, 13] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with every kind of Tri cell
    ///
    /// **WARNING:** This is not a valid FEM mesh because the cells are not compatible.
    /// We use this function to generate figures for the documentation only.
    ///
    /// ![tri_cells](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_draw_cells_and_points_work_2_tri.svg)
    #[rustfmt::skip]
    pub fn tri_cells() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0,  0.0 ] }, // 0
                Point { id: 1, marker: 0, coords: vec![1.0,  0.0 ] }, // 1
                Point { id: 2, marker: 0, coords: vec![0.5,  0.85] }, // 2

                Point { id: 3, marker: 0, coords: vec![1.2+0.0,       0.0     ] }, // 0
                Point { id: 4, marker: 0, coords: vec![1.2+1.0,       0.0     ] }, // 1
                Point { id: 5, marker: 0, coords: vec![1.2+0.5,       0.85    ] }, // 2
                Point { id: 6, marker: 0, coords: vec![1.2+0.5,       0.0-0.05] }, // 3
                Point { id: 7, marker: 0, coords: vec![1.2+0.75+0.05, 0.425   ] }, // 4
                Point { id: 8, marker: 0, coords: vec![1.2+0.25-0.05, 0.425   ] }, // 5

                Point { id:  9, marker: 0, coords: vec![0.0,        1.2+0.0       ] }, // 0
                Point { id: 10, marker: 0, coords: vec![1.0,        1.2+0.0       ] }, // 1
                Point { id: 11, marker: 0, coords: vec![0.5,        1.2+0.85      ] }, // 2
                Point { id: 12, marker: 0, coords: vec![0.333,      1.2+0.0  +0.05] }, // 3
                Point { id: 13, marker: 0, coords: vec![0.833-0.05, 1.2+0.283     ] }, // 4
                Point { id: 14, marker: 0, coords: vec![0.333+0.05, 1.2+0.567     ] }, // 5
                Point { id: 15, marker: 0, coords: vec![0.667-0.05, 1.2+0.00 -0.05] }, // 6
                Point { id: 16, marker: 0, coords: vec![0.667+0.05, 1.2+0.567     ] }, // 7
                Point { id: 17, marker: 0, coords: vec![0.167,      1.2+0.283     ] }, // 8
                Point { id: 18, marker: 0, coords: vec![0.5,        1.2+0.283     ] }, // 9

                Point { id: 19, marker: 0, coords: vec![1.2+0.0,        1.2+0.0        ] }, //  0
                Point { id: 20, marker: 0, coords: vec![1.2+1.0,        1.2+0.0        ] }, //  1
                Point { id: 21, marker: 0, coords: vec![1.2+0.5,        1.2+0.85       ] }, //  2
                Point { id: 22, marker: 0, coords: vec![1.2+0.5,        1.2+0.0        ] }, //  3
                Point { id: 23, marker: 0, coords: vec![1.2+0.75,       1.2+0.425      ] }, //  4
                Point { id: 24, marker: 0, coords: vec![1.2+0.25,       1.2+0.425      ] }, //  5
                Point { id: 25, marker: 0, coords: vec![1.2+0.25,       1.2+0.0   -0.05] }, //  6
                Point { id: 26, marker: 0, coords: vec![1.2+0.75,       1.2+0.0   +0.05] }, //  7
                Point { id: 27, marker: 0, coords: vec![1.2+0.875+0.05, 1.2+0.2125     ] }, //  8
                Point { id: 28, marker: 0, coords: vec![1.2+0.625-0.05, 1.2+0.6375     ] }, //  9
                Point { id: 29, marker: 0, coords: vec![1.2+0.375-0.05, 1.2+0.6375     ] }, // 10
                Point { id: 30, marker: 0, coords: vec![1.2+0.125+0.05, 1.2+0.2125     ] }, // 11
                Point { id: 31, marker: 0, coords: vec![1.2+0.375,      1.2+0.2125     ] }, // 12
                Point { id: 32, marker: 0, coords: vec![1.2+0.625,      1.2+0.2125     ] }, // 13
                Point { id: 33, marker: 0, coords: vec![1.2+0.5,        1.2+0.425      ] }, // 14
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3,  points: vec![0, 1, 2] },
                Cell { id: 1, marker: 1, kind: GeoKind::Tri6,  points: vec![3, 4, 5, 6, 7, 8] },
                Cell { id: 2, marker: 1, kind: GeoKind::Tri10, points: vec![9, 10, 11, 12, 13, 14, 15, 16, 17, 18] },
                Cell { id: 3, marker: 1, kind: GeoKind::Tri15, points: vec![19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with every kind of Qua cell
    ///
    /// **WARNING:** This is not a valid FEM mesh because the cells are not compatible.
    /// We use this function to generate figures for the documentation only.
    ///
    /// ![qua_cells](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_draw_cells_and_points_work_3_qua.svg)
    #[rustfmt::skip]
    pub fn qua_cells() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] }, // 0
                Point { id: 1, marker: 0, coords: vec![0.8, 0.0] }, // 1
                Point { id: 2, marker: 0, coords: vec![0.8, 0.8] }, // 2
                Point { id: 3, marker: 0, coords: vec![0.0, 0.8] }, // 3

                Point { id:  4, marker: 0, coords: vec![1.1+0.0,      0.0     ] }, // 0
                Point { id:  5, marker: 0, coords: vec![1.1+0.8,      0.0     ] }, // 1
                Point { id:  6, marker: 0, coords: vec![1.1+0.8,      0.8     ] }, // 2
                Point { id:  7, marker: 0, coords: vec![1.1+0.0,      0.8     ] }, // 3
                Point { id:  8, marker: 0, coords: vec![1.1+0.4,      0.0+0.05] }, // 4
                Point { id:  9, marker: 0, coords: vec![1.1+0.8-0.05, 0.4     ] }, // 5
                Point { id: 10, marker: 0, coords: vec![1.1+0.4,      0.8-0.05] }, // 6
                Point { id: 11, marker: 0, coords: vec![1.1+0.0-0.05, 0.4     ] }, // 7

                Point { id: 12, marker: 0, coords: vec![2.2+0.0,      0.0     ] }, // 0
                Point { id: 13, marker: 0, coords: vec![2.2+0.8,      0.0     ] }, // 1
                Point { id: 14, marker: 0, coords: vec![2.2+0.8,      0.8     ] }, // 2
                Point { id: 15, marker: 0, coords: vec![2.2+0.0,      0.8     ] }, // 3
                Point { id: 16, marker: 0, coords: vec![2.2+0.4,      0.0+0.05] }, // 4
                Point { id: 17, marker: 0, coords: vec![2.2+0.8-0.05, 0.4     ] }, // 5
                Point { id: 18, marker: 0, coords: vec![2.2+0.4,      0.8-0.05] }, // 6
                Point { id: 19, marker: 0, coords: vec![2.2+0.0-0.05, 0.4     ] }, // 7
                Point { id: 20, marker: 0, coords: vec![2.2+0.4,      0.4     ] }, // 8

                Point { id: 21, marker: 0, coords: vec![0.0,      1.2+0.0     ] }, //  0
                Point { id: 22, marker: 0, coords: vec![0.8,      1.2+0.0     ] }, //  1
                Point { id: 23, marker: 0, coords: vec![0.8,      1.2+0.8     ] }, //  2
                Point { id: 24, marker: 0, coords: vec![0.0,      1.2+0.8     ] }, //  3
                Point { id: 25, marker: 0, coords: vec![0.267,    1.2+0.0+0.03] }, //  4
                Point { id: 26, marker: 0, coords: vec![0.8-0.03, 1.2+0.267,  ] }, //  5
                Point { id: 27, marker: 0, coords: vec![0.533,    1.2+0.8-0.03] }, //  6
                Point { id: 28, marker: 0, coords: vec![0.0+0.03, 1.2+0.533,  ] }, //  7
                Point { id: 29, marker: 0, coords: vec![0.533,    1.2+0.0-0.03] }, //  8
                Point { id: 30, marker: 0, coords: vec![0.8+0.03, 1.2+0.533,  ] }, //  9
                Point { id: 31, marker: 0, coords: vec![0.267,    1.2+0.8+0.03] }, // 10
                Point { id: 32, marker: 0, coords: vec![0.0-0.03, 1.2+0.267,  ] }, // 11

                Point { id: 33, marker: 0, coords: vec![1.1+0.0,      1.2+0.0     ] }, //  0
                Point { id: 34, marker: 0, coords: vec![1.1+0.8,      1.2+0.0     ] }, //  1
                Point { id: 35, marker: 0, coords: vec![1.1+0.8,      1.2+0.8     ] }, //  2
                Point { id: 36, marker: 0, coords: vec![1.1+0.0,      1.2+0.8     ] }, //  3
                Point { id: 37, marker: 0, coords: vec![1.1+0.267,    1.2+0.0+0.03] }, //  4
                Point { id: 38, marker: 0, coords: vec![1.1+0.8-0.03, 1.2+0.267   ] }, //  5
                Point { id: 39, marker: 0, coords: vec![1.1+0.533,    1.2+0.8-0.03] }, //  6
                Point { id: 40, marker: 0, coords: vec![1.1+0.0+0.03, 1.2+0.533   ] }, //  7
                Point { id: 41, marker: 0, coords: vec![1.1+0.533,    1.2+0.0-0.03] }, //  8
                Point { id: 42, marker: 0, coords: vec![1.1+0.8+0.03, 1.2+0.533   ] }, //  9
                Point { id: 43, marker: 0, coords: vec![1.1+0.267,    1.2+0.8+0.03] }, // 10
                Point { id: 44, marker: 0, coords: vec![1.1+0.0-0.03, 1.2+0.267   ] }, // 11
                Point { id: 45, marker: 0, coords: vec![1.1+0.267,    1.2+0.267   ] }, // 12
                Point { id: 46, marker: 0, coords: vec![1.1+0.533,    1.2+0.267   ] }, // 13
                Point { id: 47, marker: 0, coords: vec![1.1+0.533,    1.2+0.533   ] }, // 14
                Point { id: 48, marker: 0, coords: vec![1.1+0.267,    1.2+0.533   ] }, // 15

                Point { id: 49, marker: 0, coords: vec![2.2+0.0,      1.2+0.0     ] }, //  0
                Point { id: 50, marker: 0, coords: vec![2.2+0.8,      1.2+0.0     ] }, //  1
                Point { id: 51, marker: 0, coords: vec![2.2+0.8,      1.2+0.8     ] }, //  2
                Point { id: 52, marker: 0, coords: vec![2.2+0.0,      1.2+0.8     ] }, //  3
                Point { id: 53, marker: 0, coords: vec![2.2+0.4,      1.2+0.0     ] }, //  4
                Point { id: 54, marker: 0, coords: vec![2.2+0.8,      1.2+0.4     ] }, //  5
                Point { id: 55, marker: 0, coords: vec![2.2+0.4,      1.2+0.8     ] }, //  6
                Point { id: 56, marker: 0, coords: vec![2.2+0.0,      1.2+0.4     ] }, //  7
                Point { id: 57, marker: 0, coords: vec![2.2+0.4,      1.2+0.4     ] }, //  8
                Point { id: 58, marker: 0, coords: vec![2.2+0.2,      1.2+0.0+0.03] }, //  9
                Point { id: 59, marker: 0, coords: vec![2.2+0.6,      1.2+0.0-0.03] }, // 10
                Point { id: 60, marker: 0, coords: vec![2.2+0.8-0.03, 1.2+0.2     ] }, // 11
                Point { id: 61, marker: 0, coords: vec![2.2+0.8+0.03, 1.2+0.6     ] }, // 12
                Point { id: 62, marker: 0, coords: vec![2.2+0.6,      1.2+0.8-0.03] }, // 13
                Point { id: 63, marker: 0, coords: vec![2.2+0.2,      1.2+0.8+0.03] }, // 14
                Point { id: 64, marker: 0, coords: vec![2.2+0.0+0.03, 1.2+0.6     ] }, // 15
                Point { id: 65, marker: 0, coords: vec![2.2+0.0-0.03, 1.2+0.2     ] }, // 16
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua4,  points: vec![0, 1, 2, 3] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua8,  points: vec![4, 5, 6, 7, 8, 9, 10, 11] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua9,  points: vec![12, 13, 14, 15, 16, 17, 18, 19, 20] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua12, points: vec![21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32] },
                Cell { id: 4, marker: 1, kind: GeoKind::Qua16, points: vec![33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48] },
                Cell { id: 5, marker: 1, kind: GeoKind::Qua17, points: vec![49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with every kind of Tet cell
    ///
    /// **WARNING:** This is not a valid FEM mesh because the cells are not compatible.
    /// We use this function to generate figures for the documentation only.
    ///
    /// ![tet_cells](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_draw_cells_and_points_work_4_tet.svg)
    #[rustfmt::skip]
    pub fn tet_cells() -> Mesh {
        let d = 0.1;
        Mesh {
            ndim: 3,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0, 0.0] }, // 0
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0, 0.0] }, // 1
                Point { id: 2, marker: 0, coords: vec![0.5, 1.0, 0.0] }, // 2
                Point { id: 3, marker: 0, coords: vec![0.5, 0.5, 1.0] }, // 3

                Point { id:  4, marker: 0, coords: vec![1.2+0.0,    0.0,  0.0] }, // 0
                Point { id:  5, marker: 0, coords: vec![1.2+1.0,    0.0,  0.0] }, // 1
                Point { id:  6, marker: 0, coords: vec![1.2+0.5,    1.0,  0.0] }, // 2
                Point { id:  7, marker: 0, coords: vec![1.2+0.5,    0.5,  1.0] }, // 3
                Point { id:  8, marker: 0, coords: vec![1.2+0.5,    0.0,  0.0] }, // 4
                Point { id:  9, marker: 0, coords: vec![1.2+0.75,   0.5,  0.0] }, // 5
                Point { id: 10, marker: 0, coords: vec![1.2+0.25+d, 0.5,  0.0] }, // 6
                Point { id: 11, marker: 0, coords: vec![1.2+0.25+d, 0.25, 0.5] }, // 7
                Point { id: 12, marker: 0, coords: vec![1.2+0.75,   0.25, 0.5] }, // 8
                Point { id: 13, marker: 0, coords: vec![1.2+0.5,    0.75, 0.5] }, // 9

                Point { id: 14, marker: 0, coords: vec![0.5+0.0,   1.2+0.0, 0.8+0.0] }, //  0
                Point { id: 15, marker: 0, coords: vec![0.5+1.2,   1.2+0.0, 0.8+0.0] }, //  1
                Point { id: 16, marker: 0, coords: vec![0.5+0.6,   1.2+1.2, 0.8+0.0] }, //  2
                Point { id: 17, marker: 0, coords: vec![0.5+0.6,   1.2+0.6, 0.8+1.2] }, //  3
                Point { id: 18, marker: 0, coords: vec![0.5+0.4,   1.2+0.0, 0.8+0.0] }, //  4
                Point { id: 19, marker: 0, coords: vec![0.5+0.8,   1.2+0.0, 0.8+0.0] }, //  5
                Point { id: 20, marker: 0, coords: vec![0.5+0.2+d, 1.2+0.4, 0.8+0.0] }, //  6
                Point { id: 21, marker: 0, coords: vec![0.5+0.4+d, 1.2+0.8, 0.8+0.0] }, //  7
                Point { id: 22, marker: 0, coords: vec![0.5+0.2+d, 1.2+0.2, 0.8+0.4] }, //  8
                Point { id: 23, marker: 0, coords: vec![0.5+0.4+d, 1.2+0.4, 0.8+0.8] }, //  9
                Point { id: 24, marker: 0, coords: vec![0.5+0.6,   1.2+1.0, 0.8+0.4] }, // 10
                Point { id: 25, marker: 0, coords: vec![0.5+0.6,   1.2+0.8, 0.8+0.8] }, // 11
                Point { id: 26, marker: 0, coords: vec![0.5+1.0,   1.2+0.2, 0.8+0.4] }, // 12
                Point { id: 27, marker: 0, coords: vec![0.5+0.8,   1.2+0.4, 0.8+0.8] }, // 13
                Point { id: 28, marker: 0, coords: vec![0.5+1.0,   1.2+0.4, 0.8+0.0] }, // 14
                Point { id: 29, marker: 0, coords: vec![0.5+0.8,   1.2+0.8, 0.8+0.0] }, // 15
                Point { id: 30, marker: 0, coords: vec![0.5+0.4,   1.2+0.6, 0.8+0.4] }, // 16
                Point { id: 31, marker: 0, coords: vec![0.5+0.6,   1.2+0.2, 0.8+0.4] }, // 17
                Point { id: 32, marker: 0, coords: vec![0.5+0.6,   1.2+0.4, 0.8+0.0] }, // 18
                Point { id: 33, marker: 0, coords: vec![0.5+0.8,   1.2+0.6, 0.8+0.4] }, // 19
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tet4,  points: vec![0, 1, 2, 3] },
                Cell { id: 1, marker: 1, kind: GeoKind::Tet10,  points: vec![4, 5, 6, 7, 8, 9, 10, 11, 12, 13] },
                Cell { id: 2, marker: 1, kind: GeoKind::Tet20,  points: vec![14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with every kind of Hex cell
    ///
    /// **WARNING:** This is not a valid FEM mesh because the cells are not compatible.
    /// We use this function to generate figures for the documentation only.
    ///
    /// ![hex_cells](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_draw_cells_and_points_work_5_hex.svg)
    #[rustfmt::skip]
    pub fn hex_cells() -> Mesh {
        let d = 0.1;
        Mesh {
            ndim: 3,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0, 0.0] }, // 0
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0, 0.0] }, // 1
                Point { id: 2, marker: 0, coords: vec![1.0, 1.0, 0.0] }, // 2
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0, 0.0] }, // 3
                Point { id: 4, marker: 0, coords: vec![0.0, 0.0, 1.0] }, // 4
                Point { id: 5, marker: 0, coords: vec![1.0, 0.0, 1.0] }, // 5
                Point { id: 6, marker: 0, coords: vec![1.0, 1.0, 1.0] }, // 6
                Point { id: 7, marker: 0, coords: vec![0.0, 1.0, 1.0] }, // 7

                Point { id:  8, marker: 0, coords: vec![1.8+0.0, 0.0,   0.0] }, //  0
                Point { id:  9, marker: 0, coords: vec![1.8+1.0, 0.0,   0.0] }, //  1
                Point { id: 10, marker: 0, coords: vec![1.8+1.0, 1.0,   0.0] }, //  2
                Point { id: 11, marker: 0, coords: vec![1.8+0.0, 1.0,   0.0] }, //  3
                Point { id: 12, marker: 0, coords: vec![1.8+0.0, 0.0,   1.0] }, //  4
                Point { id: 13, marker: 0, coords: vec![1.8+1.0, 0.0,   1.0] }, //  5
                Point { id: 14, marker: 0, coords: vec![1.8+1.0, 1.0,   1.0] }, //  6
                Point { id: 15, marker: 0, coords: vec![1.8+0.0, 1.0,   1.0] }, //  7
                Point { id: 16, marker: 0, coords: vec![1.8+0.5, 0.0-d, 0.0] }, //  8
                Point { id: 17, marker: 0, coords: vec![1.8+1.0, 0.5,   0.0] }, //  9
                Point { id: 18, marker: 0, coords: vec![1.8+0.5, 1.0+d, 0.0] }, // 10
                Point { id: 19, marker: 0, coords: vec![1.8+0.0, 0.5,   0.0] }, // 11
                Point { id: 20, marker: 0, coords: vec![1.8+0.5, 0.0-d, 1.0] }, // 12
                Point { id: 21, marker: 0, coords: vec![1.8+1.0, 0.5,   1.0] }, // 13
                Point { id: 22, marker: 0, coords: vec![1.8+0.5, 1.0+d, 1.0] }, // 14
                Point { id: 23, marker: 0, coords: vec![1.8+0.0, 0.5,   1.0] }, // 15
                Point { id: 24, marker: 0, coords: vec![1.8+0.0, 0.0,   0.5] }, // 16
                Point { id: 25, marker: 0, coords: vec![1.8+1.0, 0.0,   0.5] }, // 17
                Point { id: 26, marker: 0, coords: vec![1.8+1.0, 1.0,   0.5] }, // 18
                Point { id: 27, marker: 0, coords: vec![1.8+0.0, 1.0,   0.5] }, // 19

                Point { id: 28, marker: 0, coords: vec![0.5+0.0, 1.3+0.0,   1.3+0.0] }, //  0
                Point { id: 29, marker: 0, coords: vec![0.5+1.2, 1.3+0.0,   1.3+0.0] }, //  1
                Point { id: 30, marker: 0, coords: vec![0.5+1.2, 1.3+1.2,   1.3+0.0] }, //  2
                Point { id: 31, marker: 0, coords: vec![0.5+0.0, 1.3+1.2,   1.3+0.0] }, //  3
                Point { id: 32, marker: 0, coords: vec![0.5+0.0, 1.3+0.0,   1.3+1.2] }, //  4
                Point { id: 33, marker: 0, coords: vec![0.5+1.2, 1.3+0.0,   1.3+1.2] }, //  5
                Point { id: 34, marker: 0, coords: vec![0.5+1.2, 1.3+1.2,   1.3+1.2] }, //  6
                Point { id: 35, marker: 0, coords: vec![0.5+0.0, 1.3+1.2,   1.3+1.2] }, //  7
                Point { id: 36, marker: 0, coords: vec![0.5+0.4, 1.3+0.0-d, 1.3+0.0] }, //  8
                Point { id: 37, marker: 0, coords: vec![0.5+0.8, 1.3+0.0-d, 1.3+0.0] }, //  9
                Point { id: 38, marker: 0, coords: vec![0.5+1.2, 1.3+0.4,   1.3+0.0] }, // 10
                Point { id: 39, marker: 0, coords: vec![0.5+1.2, 1.3+0.8,   1.3+0.0] }, // 11
                Point { id: 40, marker: 0, coords: vec![0.5+0.8, 1.3+1.2+d, 1.3+0.0] }, // 12
                Point { id: 41, marker: 0, coords: vec![0.5+0.4, 1.3+1.2+d, 1.3+0.0] }, // 13
                Point { id: 42, marker: 0, coords: vec![0.5+0.0, 1.3+0.8,   1.3+0.0] }, // 14
                Point { id: 43, marker: 0, coords: vec![0.5+0.0, 1.3+0.4,   1.3+0.0] }, // 15
                Point { id: 44, marker: 0, coords: vec![0.5+0.4, 1.3+0.0-d, 1.3+1.2] }, // 16
                Point { id: 45, marker: 0, coords: vec![0.5+0.8, 1.3+0.0-d, 1.3+1.2] }, // 17
                Point { id: 46, marker: 0, coords: vec![0.5+1.2, 1.3+0.4,   1.3+1.2] }, // 18
                Point { id: 47, marker: 0, coords: vec![0.5+1.2, 1.3+0.8,   1.3+1.2] }, // 19
                Point { id: 48, marker: 0, coords: vec![0.5+0.8, 1.3+1.2+d, 1.3+1.2] }, // 20
                Point { id: 49, marker: 0, coords: vec![0.5+0.4, 1.3+1.2+d, 1.3+1.2] }, // 21
                Point { id: 50, marker: 0, coords: vec![0.5+0.0, 1.3+0.8,   1.3+1.2] }, // 22
                Point { id: 51, marker: 0, coords: vec![0.5+0.0, 1.3+0.4,   1.3+1.2] }, // 23
                Point { id: 52, marker: 0, coords: vec![0.5+0.0, 1.3+0.0,   1.3+0.4] }, // 24
                Point { id: 53, marker: 0, coords: vec![0.5+0.0, 1.3+0.0,   1.3+0.8] }, // 25
                Point { id: 54, marker: 0, coords: vec![0.5+1.2, 1.3+0.0,   1.3+0.4] }, // 26
                Point { id: 55, marker: 0, coords: vec![0.5+1.2, 1.3+0.0,   1.3+0.8] }, // 27
                Point { id: 56, marker: 0, coords: vec![0.5+1.2, 1.3+1.2,   1.3+0.4] }, // 28
                Point { id: 57, marker: 0, coords: vec![0.5+1.2, 1.3+1.2,   1.3+0.8] }, // 29
                Point { id: 58, marker: 0, coords: vec![0.5+0.0, 1.3+1.2,   1.3+0.4] }, // 30
                Point { id: 59, marker: 0, coords: vec![0.5+0.0, 1.3+1.2,   1.3+0.8] }, // 31
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex8, points: vec![0, 1, 2, 3, 4, 5, 6, 7] },
                Cell { id: 1, marker: 1, kind: GeoKind::Hex20, points: vec![8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27] },
                Cell { id: 2, marker: 1, kind: GeoKind::Hex32, points: vec![28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Lin2
    ///
    /// ```text
    ///    1
    ///   /
    ///  /
    /// 0
    /// ```
    ///
    /// ![one_lin2](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_lin2.svg)
    #[rustfmt::skip]
    pub fn one_lin2() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Lin2, points: vec![0, 1] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with Lin2 representing a graph with 8 edges
    ///
    /// ![graph_8_edges](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_graph_8_edges.svg)
    #[rustfmt::skip]
    pub fn graph_8_edges() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![314.0, 500.0 - 287.0] },
                Point { id: 1, marker: 0, coords: vec![133.0, 500.0 - 250.0] },
                Point { id: 2, marker: 0, coords: vec![205.0, 500.0 - 232.0] },
                Point { id: 3, marker: 0, coords: vec![332.0, 500.0 - 136.0] },
                Point { id: 4, marker: 0, coords: vec![280.0, 500.0 - 212.0] },
                Point { id: 5, marker: 0, coords: vec![ 79.0, 500.0 - 230.0] },
                Point { id: 6, marker: 0, coords: vec![375.0, 500.0 -  74.0] },
                Point { id: 7, marker: 0, coords: vec![ 86.0, 500.0 - 294.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Lin2, points: vec![0, 4] },
                Cell { id: 1, marker: 1, kind: GeoKind::Lin2, points: vec![1, 2] },
                Cell { id: 2, marker: 1, kind: GeoKind::Lin2, points: vec![1, 5] },
                Cell { id: 3, marker: 1, kind: GeoKind::Lin2, points: vec![1, 7] },
                Cell { id: 4, marker: 1, kind: GeoKind::Lin2, points: vec![2, 4] },
                Cell { id: 5, marker: 1, kind: GeoKind::Lin2, points: vec![3, 6] },
                Cell { id: 6, marker: 1, kind: GeoKind::Lin2, points: vec![5, 7] },
                Cell { id: 7, marker: 1, kind: GeoKind::Lin2, points: vec![3, 4] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with Lin2 representing a graph with 12 edges
    ///
    /// ```text
    ///        4------6------5
    ///        |      |    .'
    ///        |      |  .'
    /// 3------7------1.'
    /// |      |      |
    /// |      |      |
    /// 8------0------2
    /// ```
    ///
    /// ![graph_12_edges](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_graph_12_edges.svg)
    #[rustfmt::skip]
    pub fn graph_12_edges() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![1.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![2.0, 1.0] },
                Point { id: 2, marker: 0, coords: vec![2.0, 0.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0] },
                Point { id: 4, marker: 0, coords: vec![1.0, 2.0] },
                Point { id: 5, marker: 0, coords: vec![3.0, 2.0] },
                Point { id: 6, marker: 0, coords: vec![2.0, 2.0] },
                Point { id: 7, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 8, marker: 0, coords: vec![0.0, 0.0] },
            ],
            cells: vec![
                Cell { id:  0, marker: 1, kind: GeoKind::Lin2, points: vec![8, 0] },
                Cell { id:  1, marker: 1, kind: GeoKind::Lin2, points: vec![0, 2] },
                Cell { id:  2, marker: 1, kind: GeoKind::Lin2, points: vec![3, 7] },
                Cell { id:  3, marker: 1, kind: GeoKind::Lin2, points: vec![7, 1] },
                Cell { id:  4, marker: 1, kind: GeoKind::Lin2, points: vec![4, 6] },
                Cell { id:  5, marker: 1, kind: GeoKind::Lin2, points: vec![6, 5] },
                Cell { id:  6, marker: 1, kind: GeoKind::Lin2, points: vec![8, 3] },
                Cell { id:  7, marker: 1, kind: GeoKind::Lin2, points: vec![0, 7] },
                Cell { id:  8, marker: 1, kind: GeoKind::Lin2, points: vec![2, 1] },
                Cell { id:  9, marker: 1, kind: GeoKind::Lin2, points: vec![7, 4] },
                Cell { id: 10, marker: 1, kind: GeoKind::Lin2, points: vec![1, 6] },
                Cell { id: 11, marker: 1, kind: GeoKind::Lin2, points: vec![1, 5] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Tri3
    ///
    /// ```text
    ///       2
    ///      / \
    ///     /   \
    ///    /     \
    ///   /       \
    ///  /         \
    /// 0-----------1
    /// ```
    ///
    /// ![one_tri3](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_tri3.svg)
    #[rustfmt::skip]
    pub fn one_tri3() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0 ] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0 ] },
                Point { id: 2, marker: 0, coords: vec![0.5, 0.85] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![0, 1, 2] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Tri6
    ///
    /// ```text
    ///       2
    ///      / \
    ///     /   \
    ///    5     4
    ///   /       \
    ///  /         \
    /// 0-----3-----1
    /// ```
    ///
    /// ![one_tri6](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_tri6.svg)
    #[rustfmt::skip]
    pub fn one_tri6() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0,  0.0  ] },
                Point { id: 1, marker: 0, coords: vec![1.0,  0.0  ] },
                Point { id: 2, marker: 0, coords: vec![0.5,  0.85 ] },
                Point { id: 3, marker: 0, coords: vec![0.5,  0.0  ] },
                Point { id: 4, marker: 0, coords: vec![0.75, 0.425] },
                Point { id: 5, marker: 0, coords: vec![0.25, 0.425] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri6, points: vec![0, 1, 2, 3, 4, 5] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Qua4
    ///
    /// ```text
    /// 3------2
    /// |      |
    /// |      |
    /// 0------1
    /// ```
    ///
    /// ![one_qua4](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_qua4.svg)
    #[rustfmt::skip]
    pub fn one_qua4() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua4, points: vec![0, 1, 2, 3] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with two Tri3
    ///
    /// ```text
    ///      y
    ///      ^
    /// 1.0  3------------2
    ///      |`.      [1] |    [#] indicates id
    ///      |  `.    (1) |    (#) indicates marker
    ///      |    `.      |
    ///      |      `.    |
    ///      | [0]    `.  |
    ///      | (1)      `.|
    /// 0.0  0------------1 -> x
    ///     0.0          1.0
    /// ```
    ///
    /// ![two_tri3](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_two_tri3.svg)
    #[rustfmt::skip]
    pub fn two_tri3() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![0, 1, 3] },
                Cell { id: 1, marker: 1, kind: GeoKind::Tri3, points: vec![2, 3, 1] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with three Tri3
    ///
    /// ```text
    ///       4---.__
    ///      / \     `--.___3    [#] indicates id
    ///     /   \          / \   (#) indicates marker
    ///    /     \  [1]   /   \
    ///   /  [0]  \ (1)  / [2] \
    ///  /   (1)   \    /  (1)  \
    /// 0---.__     \  /      ___2
    ///        `--.__\/__.---'
    ///               1
    /// ```
    ///
    /// ![three_tri3](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_three_tri3.svg)
    #[rustfmt::skip]
    pub fn three_tri3() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.2] },
                Point { id: 1, marker: 0, coords: vec![1.2, 0.0] },
                Point { id: 2, marker: 0, coords: vec![2.2, 0.1] },
                Point { id: 3, marker: 0, coords: vec![1.8, 1.0] },
                Point { id: 4, marker: 0, coords: vec![0.5, 1.2] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![0, 1, 4] },
                Cell { id: 1, marker: 1, kind: GeoKind::Tri3, points: vec![1, 3, 4] },
                Cell { id: 2, marker: 1, kind: GeoKind::Tri3, points: vec![1, 2, 3] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with three Tri3 with one point being shared by three cells
    ///
    /// ```text
    ///            (-40) 3     [#] indicates id
    ///                 /|\    (#) indicates marker
    ///                / | \       or marker
    ///               /  |  \
    ///              /   |   \
    ///             /    |    \
    ///            / [2] | [1] \
    ///           /  (2) | (2)  \
    ///          /       |       \
    ///         /       .2.       \
    ///        /      .'   '.      \
    ///       /     .' (-30) '.     \
    ///      /    .'           '.    \
    ///     /   .'               '.   \
    ///    /  .'       [0]         '.  \
    ///   / .'         (1)           '. \
    ///  /.'                           '.\
    ///  0-------------------------------1
    /// (-10)                          (-20)
    /// ```
    ///
    /// ![three_tri3_arrow](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_three_tri3_arrow.svg)
    #[rustfmt::skip]
    pub fn three_tri3_arrow() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: -10, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: -20, coords: vec![2.0, 0.0] },
                Point { id: 2, marker: -30, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: -40, coords: vec![1.0, 2.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![0, 1, 2] },
                Cell { id: 1, marker: 2, kind: GeoKind::Tri3, points: vec![2, 1, 3] },
                Cell { id: 2, marker: 2, kind: GeoKind::Tri3, points: vec![0, 2, 3] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with three Tri6 with one point being shared by three cells
    ///
    /// ```text
    ///             (-7) 6     [#] indicates id
    ///                 /|\    (#) indicates marker
    ///                / | \       or marker
    ///               /  |  \
    ///              /   |   \
    ///             /    8    \
    ///            / [2] | [1] \
    ///           /  (2) | (2)  \
    ///          /       |       \
    ///   (-30) 9       .2.       7 (-20)
    ///        /      .'   '.      \
    ///       /     .' (-3)  '.     \
    ///      /    .'           '.    \
    ///     /   .5(-6)       (-5)4.   \
    ///    /  .'       [0]         '.  \
    ///   / .'         (1)           '. \
    ///  /.'                           '.\
    ///  0---------------3---------------1
    /// (-1)           (-10)           (-2)
    /// ```
    ///
    /// ![three_tri6_arrow](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_three_tri6_arrow.svg)
    #[rustfmt::skip]
    pub fn three_tri6_arrow() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker:  -1, coords: vec![0.0, 0.0] },
                Point { id: 1, marker:  -2, coords: vec![2.0, 0.0] },
                Point { id: 2, marker:  -3, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: -10, coords: vec![1.0, 0.0] },
                Point { id: 4, marker:  -5, coords: vec![1.5, 0.5] },
                Point { id: 5, marker:  -6, coords: vec![0.5, 0.5] },
                Point { id: 6, marker:  -7, coords: vec![1.0, 2.0] },
                Point { id: 7, marker: -20, coords: vec![1.5, 1.0] },
                Point { id: 8, marker:   0, coords: vec![1.0, 1.5] },
                Point { id: 9, marker: -30, coords: vec![0.5, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri6, points: vec![0, 1, 2, 3, 4, 5] },
                Cell { id: 1, marker: 2, kind: GeoKind::Tri6, points: vec![2, 1, 6, 4, 7, 8] },
                Cell { id: 2, marker: 2, kind: GeoKind::Tri6, points: vec![0, 2, 6, 5, 8, 9] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four tri3 cells
    ///
    /// ```text
    ///  (-4)            (-3)
    ///    3---------------2
    ///    | '.    1    .' |
    ///    |   '.     .'   |
    ///    |     '. .'     |
    ///    |  3   .1.   2  |
    ///    |    .'   '.    |
    ///    |  .'   0   '.  |
    ///    |.'           '.|
    ///    0---------------4
    ///  (-1)            (-5)
    /// ```
    ///
    /// ![four_tri3](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_four_tri3.svg)
    #[rustfmt::skip]
    pub fn four_tri3() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: -1, coords: vec![0.0, 0.0] },
                Point { id: 1, marker:  0, coords: vec![1.0, 1.0] },
                Point { id: 2, marker: -3, coords: vec![2.0, 2.0] },
                Point { id: 3, marker: -4, coords: vec![0.0, 2.0] },
                Point { id: 4, marker: -5, coords: vec![2.0, 0.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![1, 0, 4] },
                Cell { id: 1, marker: 1, kind: GeoKind::Tri3, points: vec![1, 2, 3] },
                Cell { id: 2, marker: 1, kind: GeoKind::Tri3, points: vec![1, 4, 2] },
                Cell { id: 3, marker: 1, kind: GeoKind::Tri3, points: vec![1, 3, 0] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with two Tri3 and one Qua4
    ///
    /// ```text
    ///      y
    ///      ^
    ///     +2           +2           +2
    /// 1.0  3------------2------------5
    ///      |`.      [1] |            |    [#] indicates id
    ///      |  `.    (1) |            |    (#) indicates marker
    ///      |    `.      |     [2]    |
    ///      |      `.    |     (2)    |
    ///      | [0]    `.  |            |
    ///      | (1)      `.|            |
    /// 0.0  0------------1------------4 -> x
    ///     0.0          1.0          2.0
    ///     +1           +1           +1
    /// ```
    ///
    /// ![two_tri3_one_qua4](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_two_tri3_one_qua4.svg)
    #[rustfmt::skip]
    pub fn two_tri3_one_qua4() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 1, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 1, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: 2, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: 2, coords: vec![0.0, 1.0] },
                Point { id: 4, marker: 1, coords: vec![2.0, 0.0] },
                Point { id: 5, marker: 2, coords: vec![2.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![0, 1, 3] },
                Cell { id: 1, marker: 1, kind: GeoKind::Tri3, points: vec![2, 3, 1] },
                Cell { id: 2, marker: 2, kind: GeoKind::Qua4, points: vec![1, 4, 5, 2] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with a tri3, a qua4, and a lin2
    ///
    /// ![tri3_qua4_lin2](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_tri3_qua4_lin2.svg)
    #[rustfmt::skip]
    pub fn tri3_qua4_lin2() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.5, 0.0 ] },
                Point { id: 1, marker: 0, coords: vec![0.0, 0.85] },
                Point { id: 2, marker: 0, coords: vec![0.1, 1.7 ] },
                Point { id: 3, marker: 0, coords: vec![1.1, 1.6 ] },
                Point { id: 4, marker: 0, coords: vec![1.0, 0.75] },
                Point { id: 5, marker: 0, coords: vec![1.5, 1.8 ] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tri3, points: vec![0, 4, 1] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua4, points: vec![1, 4, 3, 2] },
                Cell { id: 2, marker: 1, kind: GeoKind::Lin2, points: vec![3, 5] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Qua8
    ///
    /// ```text
    ///      y
    ///      ^
    /// 1.0  3------6------2
    ///      |             |    [#] indicates id
    ///      |             |    (#) indicates marker
    ///      7     [0]     5
    ///      |     (1)     |
    ///      |             |
    /// 0.0  0------4------1 -> x
    ///     0.0           1.0
    /// ```
    ///
    /// ![one_qua8](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_qua8.svg)
    #[rustfmt::skip]
    pub fn one_qua8() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0] },
                Point { id: 4, marker: 0, coords: vec![0.5, 0.0] },
                Point { id: 5, marker: 0, coords: vec![1.0, 0.5] },
                Point { id: 6, marker: 0, coords: vec![0.5, 1.0] },
                Point { id: 7, marker: 0, coords: vec![0.0, 0.5] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua8, points: vec![0, 1, 2, 3, 4, 5, 6, 7] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns two quadrilaterals along the horizontal
    ///
    /// ```text
    ///          [#] indicates id
    ///      y   (#) indicates marker
    ///      ↑   -100        -200
    /// 1.0  3-----------2-----------5
    ///      |(-4)       |(-3)       |(-6)
    ///  -300|    [0]    |    [1]    |-300
    ///      |    (1)    |    (2)    |
    ///      |(-1)       |(-2)       |(-5)
    /// 0.0  0-----------1-----------4  → x
    ///     0.0  -400   1.0  -400   2.0
    /// ```
    ///
    /// ![two_qua4](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_two_qua4.svg)
    #[rustfmt::skip]
    pub fn two_qua4() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: -1, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: -2, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: -3, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: -4, coords: vec![0.0, 1.0] },
                Point { id: 4, marker: -5, coords: vec![2.0, 0.0] },
                Point { id: 5, marker: -6, coords: vec![2.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua4, points: vec![0, 1, 2, 3] },
                Cell { id: 1, marker: 2, kind: GeoKind::Qua4, points: vec![1, 4, 5, 2] },
            ],
            marked_edges: vec![
                (-100, 3, 2),
                (-200, 2, 5),
                (-300, 5, 4), (-300, 3, 0),
                (-400, 0, 1), (-400, 1, 4),
            ],
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Qua8, one Tri6, and two Lin2
    ///
    /// ```text
    /// -500        -400
    /// 8------7------6._
    /// |       [3](3)|  '-.5
    /// |  [0]        |     '-._
    /// 9  (1)       10  [1]    '4 -300
    /// |             |  (2)  .-'
    /// |       [2](3)|   _.3'
    /// 0------1------2.-'
    /// -100         -200
    /// ```
    ///
    /// ![qua8_tri6_lin2](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_qua8_tri6_lin2.svg)
    #[rustfmt::skip]
    pub fn qua8_tri6_lin2() -> Mesh {
        let h = 0.866; // ~ SQRT_3 / 2
        let m = h / 2.0;
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker: -100, coords: vec![0.0,   0.0 ] },
                Point { id:  1, marker:    0, coords: vec![0.5,   0.0 ] },
                Point { id:  2, marker: -200, coords: vec![1.0,   0.0 ] },
                Point { id:  3, marker:    0, coords: vec![1.0+m, 0.25] },
                Point { id:  4, marker: -300, coords: vec![1.0+h, 0.5 ] },
                Point { id:  5, marker:    0, coords: vec![1.0+m, 0.75] },
                Point { id:  6, marker: -400, coords: vec![1.0,   1.0 ] },
                Point { id:  7, marker:    0, coords: vec![0.5,   1.0 ] },
                Point { id:  8, marker: -500, coords: vec![0.0,   1.0 ] },
                Point { id:  9, marker:    0, coords: vec![0.0,   0.5 ] },
                Point { id: 10, marker:    0, coords: vec![1.0,   0.5 ] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua8, points: vec![0, 2, 6, 8, 1, 10, 7, 9] },
                Cell { id: 1, marker: 2, kind: GeoKind::Tri6, points: vec![2, 4, 6, 3, 5, 10] },
                Cell { id: 2, marker: 3, kind: GeoKind::Lin2, points: vec![2, 10] },
                Cell { id: 3, marker: 3, kind: GeoKind::Lin2, points: vec![10, 6] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Qua8, one Tri6, and two Lin2 in three-dimensional space
    ///
    /// ```text
    ///     -500        -400
    ///       8------7------6._
    ///      /        [3](3)/  '-.5
    ///     /  [0]         /      '-._
    ///    9  (1)        10  [1]     _'4 -300
    ///   /              /  (2)  .-'
    ///  /        [2](3)/  __.3'
    /// 0------1------2.-''
    /// -100         -200
    /// ```
    #[rustfmt::skip]
    pub fn qua8_tri6_lin2_three_dimensional() -> Mesh {
        let h = 0.866; // ~ SQRT_3 / 2
        let m = h / 2.0;
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: -100, coords: vec![0.0,   0.0 , 0.5] },
                Point { id:  1, marker:    0, coords: vec![0.5,   0.0 , 0.2] },
                Point { id:  2, marker: -200, coords: vec![1.0,   0.0 , 0.4] },
                Point { id:  3, marker:    0, coords: vec![1.0+m, 0.25, 1.0] },
                Point { id:  4, marker: -300, coords: vec![1.0+h, 0.5 , 2.0] },
                Point { id:  5, marker:    0, coords: vec![1.0+m, 0.75, 1.0] },
                Point { id:  6, marker: -400, coords: vec![1.0,   1.0 , 0.4] },
                Point { id:  7, marker:    0, coords: vec![0.5,   1.0 , 0.2] },
                Point { id:  8, marker: -500, coords: vec![0.0,   1.0 , 0.5] },
                Point { id:  9, marker:    0, coords: vec![0.0,   0.5 , 0.5] },
                Point { id: 10, marker:    0, coords: vec![1.0,   0.5 , 0.4] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua8, points: vec![0, 2, 6, 8, 1, 10, 7, 9] },
                Cell { id: 1, marker: 2, kind: GeoKind::Tri6, points: vec![2, 4, 6, 3, 5, 10] },
                Cell { id: 2, marker: 3, kind: GeoKind::Lin2, points: vec![2, 10] },
                Cell { id: 3, marker: 3, kind: GeoKind::Lin2, points: vec![10, 6] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Tet4
    ///
    /// ![one_tet4](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_tet4.svg)
    #[rustfmt::skip]
    pub fn one_tet4() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 0.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tet4, points: vec![0, 1, 2, 3] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Tet10
    #[rustfmt::skip]
    pub fn one_tet10(d: f64) -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id: 0, marker: -1, coords: vec![0.0  , 0.0  , 0.0] },
                Point { id: 1, marker: -1, coords: vec![1.0  , 0.0  , 0.0] },
                Point { id: 2, marker: -1, coords: vec![0.0  , 1.0  , 0.0] },
                Point { id: 3, marker: -1, coords: vec![0.0  , 0.0  , 1.0] },
                Point { id: 4, marker: -2, coords: vec![0.5+d, 0.0  , 0.0] },
                Point { id: 5, marker: -2, coords: vec![0.5-d, 0.5-d, 0.0] },
                Point { id: 6, marker: -2, coords: vec![0.0+d, 0.5  , 0.0] },
                Point { id: 7, marker: -2, coords: vec![0.0+d, 0.0+d, 0.5] },
                Point { id: 8, marker: -2, coords: vec![0.5  , 0.0  , 0.5] },
                Point { id: 9, marker: -2, coords: vec![0.0  , 0.5  , 0.5] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Tet10, points: vec![0,1,2,3,4,5,6,7,8,9] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with one Hex8
    ///
    /// ```text
    ///       4--------------7  1.0
    ///      /.             /|
    ///     / .            / |    [#] indicates id
    ///    /  .           /  |    (#) indicates marker
    ///   /   .          /   |
    ///  5--------------6    |          z
    ///  |    .         |    |          ↑
    ///  |    0---------|----3  0.0     o → y
    ///  |   /  [0]     |   /          ↙
    ///  |  /   (1)     |  /          x
    ///  | /            | /
    ///  |/             |/
    ///  1--------------2   1.0
    /// 0.0            1.0
    /// ```
    ///
    /// ![one_hex8](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_one_hex8.svg)
    #[rustfmt::skip]
    pub fn one_hex8() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![1.0, 1.0, 0.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id: 4, marker: 0, coords: vec![0.0, 0.0, 1.0] },
                Point { id: 5, marker: 0, coords: vec![1.0, 0.0, 1.0] },
                Point { id: 6, marker: 0, coords: vec![1.0, 1.0, 1.0] },
                Point { id: 7, marker: 0, coords: vec![0.0, 1.0, 1.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex8, points: vec![0,1,2,3, 4,5,6,7] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns two cubes along the vertical
    ///
    /// ```text
    ///           [#] indicates id
    ///           (#) indicates marker
    ///           {#} indicates marker
    ///             * indicates points marked with -1
    ///
    ///       8-------------11  2.0
    ///      /.             /|
    /// {-5}/ .        {-5}/ |
    ///    /  .   {-9}    /  |
    ///   /   .          /   |{123}
    ///  9-------------10    |
    ///  |    .         |    |
    ///  |    4---------|----7* 1.0
    ///  |   /. [1]     |   /|
    ///  |  / . (2)     |  / |
    ///  | /  .         | /  |
    ///  |/   .         |/   |{-4}
    ///  5--------------6    |          z
    ///  |{-11}         |{-8}|          ↑
    ///  |    0---------|----3  0.0     o → y
    ///  |   /  [0]     |   /          ↙
    ///  |  /   (1)     |  /          x
    ///  | /            | /
    ///  |/   {-10}     |/
    ///  1*-------------2*  1.0
    /// 0.0            1.0
    /// ```
    ///
    /// ![two_hex8](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_two_hex8.svg)
    #[rustfmt::skip]
    pub fn two_hex8() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id:  1, marker:-1, coords: vec![1.0, 0.0, 0.0] },
                Point { id:  2, marker:-1, coords: vec![1.0, 1.0, 0.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id:  4, marker: 0, coords: vec![0.0, 0.0, 1.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.0, 1.0] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.0, 1.0] },
                Point { id:  7, marker:-1, coords: vec![0.0, 1.0, 1.0] },
                Point { id:  8, marker: 0, coords: vec![0.0, 0.0, 2.0] },
                Point { id:  9, marker: 0, coords: vec![1.0, 0.0, 2.0] },
                Point { id: 10, marker: 0, coords: vec![1.0, 1.0, 2.0] },
                Point { id: 11, marker: 0, coords: vec![0.0, 1.0, 2.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex8, points: vec![0,1,2,3, 4,5,6,7] },
                Cell { id: 1, marker: 2, kind: GeoKind::Hex8, points: vec![4,5,6,7, 8,9,10,11] },
            ],
            marked_edges: vec![(123, 7, 11), (-5, 11, 10), (-4, 7, 3), (-5, 8, 9)],
            marked_faces: vec![(-8, 3, 2, 7, 6), (-9, 8, 10, 9, 11), (-10, 1, 2, 5, 6), (-11, 0, 1, 4, 5)]
        }
    }

    /// Returns four cubes making a vertical wall
    ///
    /// ```text
    ///           [#] indicates id
    ///           (#) indicates marker
    ///           {#} indicates marker
    ///
    ///       8-------------11-------------17  2.0
    ///      /.             /.             /|
    ///     / .  {-100}    / .  {-200}    / |
    ///    /  .           /  .           /  |
    ///   /   .          /   .          /   |
    ///  9=============10=============16    |
    ///  |    .         |    .         |    |
    ///  |    4---------|----7---------|---15  1.0
    ///  |   /. [1]     |   /. [3]     |   /|
    ///  |  / . (2)     |  / . (2)     |  / |
    ///  | /  .         | /  .         | /  |
    ///  |/   .         |/   .         |/   |
    ///  5--------------6-------------14    |          z
    ///  |    .         |    .         |    |          ↑
    ///  |    0---------|----3---------|---13  0.0     o → y
    ///  |   /  [0]     |   /  [2]     |   /          ↙
    ///  |  /   (1)     |  /   (1)     |  /          x
    ///  | /            | /            | /
    ///  |/             |/             |/
    ///  1--------------2-------------12   1.0
    /// 0.0            1.0            2.0
    /// ```
    ///
    /// ![four_hex8](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_four_hex8.svg)
    #[rustfmt::skip]
    pub fn four_hex8() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.0, 0.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.0, 1.0, 0.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id:  4, marker: 0, coords: vec![0.0, 0.0, 1.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.0, 1.0] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.0, 1.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0, 1.0] },
                Point { id:  8, marker:-1, coords: vec![0.0, 0.0, 2.0] },
                Point { id:  9, marker: 0, coords: vec![1.0, 0.0, 2.0] },
                Point { id: 10, marker: 0, coords: vec![1.0, 1.0, 2.0] },
                Point { id: 11, marker: 0, coords: vec![0.0, 1.0, 2.0] },
                Point { id: 12, marker: 0, coords: vec![1.0, 2.0, 0.0] },
                Point { id: 13, marker: 0, coords: vec![0.0, 2.0, 0.0] },
                Point { id: 14, marker: 0, coords: vec![1.0, 2.0, 1.0] },
                Point { id: 15, marker: 0, coords: vec![0.0, 2.0, 1.0] },
                Point { id: 16, marker: 0, coords: vec![1.0, 2.0, 2.0] },
                Point { id: 17, marker: 0, coords: vec![0.0, 2.0, 2.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex8, points: vec![0,1, 2, 3,  4, 5, 6, 7] },
                Cell { id: 1, marker: 2, kind: GeoKind::Hex8, points: vec![4,5, 6, 7,  8, 9,10,11] },
                Cell { id: 2, marker: 1, kind: GeoKind::Hex8, points: vec![3,2,12,13,  7, 6,14,15] },
                Cell { id: 3, marker: 2, kind: GeoKind::Hex8, points: vec![7,6,14,15, 11,10,16,17] },
            ],
            marked_edges: Vec::new(),
            marked_faces: vec![(-100, 8, 9,10,11), (-200,10,11,16,17)],
        }
    }

    /// Returns a mesh with one Hex20
    ///
    /// ```text
    ///             4_______15_______7
    ///           ,'|              ,'|
    ///        12'  |            ,'  |
    ///       ,'    16         ,14   |
    ///     ,'      |        ,'      19
    ///   5'=====13========6'        |
    ///   |         |      |         |
    ///   |         |      |         |
    ///   |         0_____ | _11_____3
    ///  17       ,'       |       ,'
    ///   |     8'        18     ,'
    ///   |   ,'           |   ,10
    ///   | ,'             | ,'
    ///   1_______9________2'
    /// ```
    #[rustfmt::skip]
    pub fn one_hex20(d: f64, e: f64, f:f64) -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: -1, coords: vec![0.0  , 0.0  , 0.0  ] }, //  0
                Point { id:  1, marker: -1, coords: vec![1.0  , 0.0  , 0.0  ] }, //  1
                Point { id:  2, marker: -1, coords: vec![1.0  , 1.0  , 0.0  ] }, //  2
                Point { id:  3, marker: -1, coords: vec![0.0  , 1.0  , 0.0  ] }, //  3
                Point { id:  4, marker: -2, coords: vec![0.0  , 0.0  , 1.0  ] }, //  4
                Point { id:  5, marker: -2, coords: vec![1.0  , 0.0  , 1.0  ] }, //  5
                Point { id:  6, marker: -2, coords: vec![1.0  , 1.0  , 1.0  ] }, //  6
                Point { id:  7, marker: -2, coords: vec![0.0  , 1.0  , 1.0  ] }, //  7
                Point { id:  8, marker: -1, coords: vec![0.5  , 0.0+d, 0.0  ] }, //  8
                Point { id:  9, marker: -1, coords: vec![1.0-d, 0.5  , 0.0  ] }, //  9
                Point { id: 10, marker: -1, coords: vec![0.5  , 1.0-d, 0.0  ] }, // 10
                Point { id: 11, marker: -1, coords: vec![0.0+d, 0.5  , 0.0  ] }, // 11
                Point { id: 12, marker: -2, coords: vec![0.5  , 0.0+e, 1.0+f] }, // 12
                Point { id: 13, marker: -2, coords: vec![1.0-e, 0.5  , 1.0  ] }, // 13
                Point { id: 14, marker: -2, coords: vec![0.5  , 1.0-e, 1.0+f] }, // 14
                Point { id: 15, marker: -2, coords: vec![0.0+e, 0.5  , 1.0  ] }, // 15
                Point { id: 16, marker: -3, coords: vec![0.0  , 0.0  , 0.5  ] }, // 16
                Point { id: 17, marker: -3, coords: vec![1.0  , 0.0  , 0.5  ] }, // 17
                Point { id: 18, marker: -3, coords: vec![1.0  , 1.0  , 0.5  ] }, // 18
                Point { id: 19, marker: -3, coords: vec![0.0  , 1.0  , 0.5  ] }, // 19
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex20, points: vec![0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with mixed shapes in 2D
    ///
    /// ```text
    /// 1.0              4-----------3
    ///                  |           |
    ///                  |    [1]    |   [*] indicates id
    ///                  |    (2)    |   (*) indicates marker
    ///                  |           |
    /// 0.0  0-----------1-----------2-----------5
    ///           [0]                     [2]
    ///           (1)                     (1)
    ///
    ///     0.0         1.0         2.0         3.0
    /// ```
    ///
    /// ![mixed_shapes_2d](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_mixed_shapes_2d.svg)
    #[rustfmt::skip]
    pub fn mixed_shapes_2d() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![2.0, 0.0] },
                Point { id: 3, marker: 0, coords: vec![2.0, 1.0] },
                Point { id: 4, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 5, marker: 0, coords: vec![3.0, 0.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Lin2, points: vec![0, 1] },
                Cell { id: 1, marker: 2, kind: GeoKind::Qua4, points: vec![1, 2, 3, 4] },
                Cell { id: 2, marker: 1, kind: GeoKind::Lin2, points: vec![2, 5] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with mixed shapes in 3D
    ///
    /// **Note:** There is a tetrahedron (Tet4) on with nodes (2,8,3,6).
    ///
    /// ```text
    /// Note: the tetrahedron (2,8,3,6) is incompatible
    ///                       4------------7-----------10
    ///                      /.           /|            |
    ///                     / .          / |            |
    ///                    /  .         /  |            |
    ///                   /   .        /   |            |
    ///         z        5------------6    |            |
    ///         ↑        |    .       |`.  |            |
    ///         o → x    |    0-------|--`.3------------9
    ///        ↙         |   /        |   /`.          /
    ///      x           |  /         |  /   `.       /
    ///                  | /          | /      `.    /
    ///                  |/           |/         `. /
    ///  12-----11-------1------------2------------8
    /// ```
    ///
    /// ![mixed_shapes_3d](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_mixed_shapes_3d.svg)
    #[rustfmt::skip]
    pub fn mixed_shapes_3d() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.0, 0.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.0, 1.0, 0.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id:  4, marker: 0, coords: vec![0.0, 0.0, 1.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.0, 1.0] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.0, 1.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0, 1.0] },
                Point { id:  8, marker: 0, coords: vec![1.0, 2.0, 0.0] },
                Point { id:  9, marker: 0, coords: vec![0.0, 2.0, 0.0] },
                Point { id: 10, marker: 0, coords: vec![0.0, 2.0, 1.0] },
                Point { id: 11, marker: 0, coords: vec![1.0,-0.5, 0.0] },
                Point { id: 12, marker: 0, coords: vec![1.0,-1.0, 0.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex8, points: vec![0,1,2,3,4,5,6,7] },
                Cell { id: 1, marker: 2, kind: GeoKind::Tet4, points: vec![2,8,3,6] },
                Cell { id: 2, marker: 2, kind: GeoKind::Qua4, points: vec![3,9,10,7] },
                Cell { id: 3, marker: 2, kind: GeoKind::Tri3, points: vec![8,9,3] },
                Cell { id: 4, marker: 3, kind: GeoKind::Lin3, points: vec![1,12,11] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four qua4 cells
    ///
    /// ```text
    ///             -300            -300
    /// 2.0   7---------------6---------------8
    ///       |               |               |
    ///       |               |               |
    ///   -400|      [2]      |      [3]      |-200
    ///       |               |               |
    ///       |               |               |
    /// 1.0   3---------------2---------------5
    ///       |               |               |
    ///       |               |               |
    ///   -400|      [0]      |      [1]      |-200
    ///       |               |               |
    ///       |               |               |
    /// 0.0   0---------------1---------------4
    ///             -100            -100
    ///      0.0             1.0             2.0
    ///
    /// xmin = 0.0, xmax = 2.0
    /// ymin = 0.0, ymax = 2.0
    /// ```
    ///
    /// ![block_2d_four_qua4](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_2d_four_qua4.svg)
    #[rustfmt::skip]
    pub fn block_2d_four_qua4() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id: 1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id: 2, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 3, marker: 0, coords: vec![0.0, 1.0] },
                Point { id: 4, marker: 0, coords: vec![2.0, 0.0] },
                Point { id: 5, marker: 0, coords: vec![2.0, 1.0] },
                Point { id: 6, marker: 0, coords: vec![1.0, 2.0] },
                Point { id: 7, marker: 0, coords: vec![0.0, 2.0] },
                Point { id: 8, marker: 0, coords: vec![2.0, 2.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua4, points: vec![0, 1, 2, 3] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua4, points: vec![1, 4, 5, 2] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua4, points: vec![3, 2, 6, 7] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua4, points: vec![2, 5, 8, 6] },
            ],
            marked_edges: vec![
                (-100, 0, 1),
                (-400, 0, 3),
                (-100, 1, 4),
                (-200, 4, 5),
                (-300, 6, 7),
                (-400, 3, 7),
                (-200, 5, 8),
                (-300, 6, 8),
            ],
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four qua8 cells
    ///
    /// ```text
    /// 2.0  14------16------13------20------18
    ///       |               |               |
    ///       |               |               |
    /// 1.5  17      [2]     15      [3]     19
    ///       |               |               |
    ///       |               |               |
    /// 1.0   3-------6-------2------12-------9
    ///       |               |               |
    ///       |               |               |
    /// 0.5   7      [0]      5      [1]     11
    ///       |               |               |
    ///       |               |               |
    /// 0.0   0-------4-------1------10-------8
    ///
    ///      0.0     0.5     1.0     1.5     2.0
    ///
    /// xmin = 0.0, xmax = 2.0
    /// ymin = 0.0, ymax = 2.0
    /// ```
    ///
    /// ![block_2d_four_qua8](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_2d_four_qua8.svg)
    #[rustfmt::skip]
    pub fn block_2d_four_qua8() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.0, 1.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0] },
                Point { id:  4, marker: 0, coords: vec![0.5, 0.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.5] },
                Point { id:  6, marker: 0, coords: vec![0.5, 1.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 0.5] },
                Point { id:  8, marker: 0, coords: vec![2.0, 0.0] },
                Point { id:  9, marker: 0, coords: vec![2.0, 1.0] },
                Point { id: 10, marker: 0, coords: vec![1.5, 0.0] },
                Point { id: 11, marker: 0, coords: vec![2.0, 0.5] },
                Point { id: 12, marker: 0, coords: vec![1.5, 1.0] },
                Point { id: 13, marker: 0, coords: vec![1.0, 2.0] },
                Point { id: 14, marker: 0, coords: vec![0.0, 2.0] },
                Point { id: 15, marker: 0, coords: vec![1.0, 1.5] },
                Point { id: 16, marker: 0, coords: vec![0.5, 2.0] },
                Point { id: 17, marker: 0, coords: vec![0.0, 1.5] },
                Point { id: 18, marker: 0, coords: vec![2.0, 2.0] },
                Point { id: 19, marker: 0, coords: vec![2.0, 1.5] },
                Point { id: 20, marker: 0, coords: vec![1.5, 2.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua8, points: vec![0, 1,  2,  3,  4,  5,  6,  7] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua8, points: vec![1, 8,  9,  2, 10, 11, 12,  5] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua8, points: vec![3, 2, 13, 14,  6, 15, 16, 17] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua8, points: vec![2, 9, 18, 13, 12, 19, 20, 15] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four qua9 cells
    ///
    /// ```text
    /// cell ids as in block_2d_four_qua8
    ///
    /// 2.0  16------18------15------23------21
    ///       |               |               |
    ///       |               |               |
    /// 1.5  19      20      17      24      22
    ///       |               |               |
    ///       |               |               |
    /// 1.0   3-------6-------2------13------10
    ///       |               |               |
    ///       |               |               |
    /// 0.5   7       8       5      14      12
    ///       |               |               |
    ///       |               |               |
    /// 0.0   0-------4-------1------11-------9
    ///
    ///      0.0     0.5     1.0     1.5     2.0
    ///
    /// xmin = 0.0, xmax = 2.0
    /// ymin = 0.0, ymax = 2.0
    /// ```
    ///
    /// ![block_2d_four_qua9](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_2d_four_qua9.svg)
    #[rustfmt::skip]
    pub fn block_2d_four_qua9() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.0, 1.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0] },
                Point { id:  4, marker: 0, coords: vec![0.5, 0.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.5] },
                Point { id:  6, marker: 0, coords: vec![0.5, 1.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 0.5] },
                Point { id:  8, marker: 0, coords: vec![0.5, 0.5] },
                Point { id:  9, marker: 0, coords: vec![2.0, 0.0] },
                Point { id: 10, marker: 0, coords: vec![2.0, 1.0] },
                Point { id: 11, marker: 0, coords: vec![1.5, 0.0] },
                Point { id: 12, marker: 0, coords: vec![2.0, 0.5] },
                Point { id: 13, marker: 0, coords: vec![1.5, 1.0] },
                Point { id: 14, marker: 0, coords: vec![1.5, 0.5] },
                Point { id: 15, marker: 0, coords: vec![1.0, 2.0] },
                Point { id: 16, marker: 0, coords: vec![0.0, 2.0] },
                Point { id: 17, marker: 0, coords: vec![1.0, 1.5] },
                Point { id: 18, marker: 0, coords: vec![0.5, 2.0] },
                Point { id: 19, marker: 0, coords: vec![0.0, 1.5] },
                Point { id: 20, marker: 0, coords: vec![0.5, 1.5] },
                Point { id: 21, marker: 0, coords: vec![2.0, 2.0] },
                Point { id: 22, marker: 0, coords: vec![2.0, 1.5] },
                Point { id: 23, marker: 0, coords: vec![1.5, 2.0] },
                Point { id: 24, marker: 0, coords: vec![1.5, 1.5] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua9, points: vec![0,  1,  2,  3,  4,  5,  6,  7,  8] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua9, points: vec![1,  9, 10,  2, 11, 12, 13,  5, 14] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua9, points: vec![3,  2, 15, 16,  6, 17, 18, 19, 20] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua9, points: vec![2, 10, 21, 15, 13, 22, 23, 17, 24] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four qua12 cells
    ///
    /// ```text
    /// cell ids as in block_2d_four_qua8
    ///
    /// 3.0  21---26---23----20---32---30----28
    ///       |               |               |
    /// 2.5  24              25              31
    ///       |               |               |
    /// 2.0  27              22              29
    ///       |               |               |
    /// 1.5   3---10-----6----2---19---16----13
    ///       |               |               |
    /// 1.0   7               9              18
    ///       |               |               |
    /// 0.5  11               5              15
    ///       |               |               |
    /// 0.0   0----4-----8----1---14---17----12
    ///
    ///      0.0  0.5   1.0  1.5  2.0  2.5   3.0
    ///
    /// xmin = 0.0, xmax = 3.0
    /// ymin = 0.0, ymax = 3.0
    /// ```
    ///
    /// ![block_2d_four_qua12](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_2d_four_qua12.svg)
    #[rustfmt::skip]
    pub fn block_2d_four_qua12() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.5, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.5, 1.5] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.5] },
                Point { id:  4, marker: 0, coords: vec![0.5, 0.0] },
                Point { id:  5, marker: 0, coords: vec![1.5, 0.5] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.5] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0] },
                Point { id:  8, marker: 0, coords: vec![1.0, 0.0] },
                Point { id:  9, marker: 0, coords: vec![1.5, 1.0] },
                Point { id: 10, marker: 0, coords: vec![0.5, 1.5] },
                Point { id: 11, marker: 0, coords: vec![0.0, 0.5] },
                Point { id: 12, marker: 0, coords: vec![3.0, 0.0] },
                Point { id: 13, marker: 0, coords: vec![3.0, 1.5] },
                Point { id: 14, marker: 0, coords: vec![2.0, 0.0] },
                Point { id: 15, marker: 0, coords: vec![3.0, 0.5] },
                Point { id: 16, marker: 0, coords: vec![2.5, 1.5] },
                Point { id: 17, marker: 0, coords: vec![2.5, 0.0] },
                Point { id: 18, marker: 0, coords: vec![3.0, 1.0] },
                Point { id: 19, marker: 0, coords: vec![2.0, 1.5] },
                Point { id: 20, marker: 0, coords: vec![1.5, 3.0] },
                Point { id: 21, marker: 0, coords: vec![0.0, 3.0] },
                Point { id: 22, marker: 0, coords: vec![1.5, 2.0] },
                Point { id: 23, marker: 0, coords: vec![1.0, 3.0] },
                Point { id: 24, marker: 0, coords: vec![0.0, 2.5] },
                Point { id: 25, marker: 0, coords: vec![1.5, 2.5] },
                Point { id: 26, marker: 0, coords: vec![0.5, 3.0] },
                Point { id: 27, marker: 0, coords: vec![0.0, 2.0] },
                Point { id: 28, marker: 0, coords: vec![3.0, 3.0] },
                Point { id: 29, marker: 0, coords: vec![3.0, 2.0] },
                Point { id: 30, marker: 0, coords: vec![2.5, 3.0] },
                Point { id: 31, marker: 0, coords: vec![3.0, 2.5] },
                Point { id: 32, marker: 0, coords: vec![2.0, 3.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua12, points: vec![0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua12, points: vec![1, 12, 13,  2, 14, 15, 16,  9, 17, 18, 19,  5] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua12, points: vec![3,  2, 20, 21, 10, 22, 23, 24,  6, 25, 26, 27] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua12, points: vec![2, 13, 28, 20, 19, 29, 30, 25, 16, 31, 32, 22] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four qua16 cells
    ///
    /// ```text
    /// cell ids as in block_2d_four_qua8
    ///
    /// 3.0  29---34----31---28---44---42----40
    ///       |               |               |
    /// 2.5  32   39    38   33   48   47    43
    ///       |               |               |
    /// 2.0  35   36    37   30   45   46    41
    ///       |               |               |
    /// 1.5   3---10-----6----2---23---20----17
    ///       |               |               |
    /// 1.0   7   15    14    9   27   26    22
    ///       |               |               |
    /// 0.5  11   12    13    5   24   25    19
    ///       |               |               |
    /// 0.0   0----4-----8----1---18---21----16
    ///
    ///      0.0  0.5   1.0  1.5  2.0  2.5   3.0
    ///
    /// xmin = 0.0, xmax = 3.0
    /// ymin = 0.0, ymax = 3.0
    /// ```
    ///
    /// ![block_2d_four_qua16](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_2d_four_qua16.svg)
    #[rustfmt::skip]
    pub fn block_2d_four_qua16() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.5, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.5, 1.5] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.5] },
                Point { id:  4, marker: 0, coords: vec![0.5, 0.0] },
                Point { id:  5, marker: 0, coords: vec![1.5, 0.5] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.5] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0] },
                Point { id:  8, marker: 0, coords: vec![1.0, 0.0] },
                Point { id:  9, marker: 0, coords: vec![1.5, 1.0] },
                Point { id: 10, marker: 0, coords: vec![0.5, 1.5] },
                Point { id: 11, marker: 0, coords: vec![0.0, 0.5] },
                Point { id: 12, marker: 0, coords: vec![0.5, 0.5] },
                Point { id: 13, marker: 0, coords: vec![1.0, 0.5] },
                Point { id: 14, marker: 0, coords: vec![1.0, 1.0] },
                Point { id: 15, marker: 0, coords: vec![0.5, 1.0] },
                Point { id: 16, marker: 0, coords: vec![3.0, 0.0] },
                Point { id: 17, marker: 0, coords: vec![3.0, 1.5] },
                Point { id: 18, marker: 0, coords: vec![2.0, 0.0] },
                Point { id: 19, marker: 0, coords: vec![3.0, 0.5] },
                Point { id: 20, marker: 0, coords: vec![2.5, 1.5] },
                Point { id: 21, marker: 0, coords: vec![2.5, 0.0] },
                Point { id: 22, marker: 0, coords: vec![3.0, 1.0] },
                Point { id: 23, marker: 0, coords: vec![2.0, 1.5] },
                Point { id: 24, marker: 0, coords: vec![2.0, 0.5] },
                Point { id: 25, marker: 0, coords: vec![2.5, 0.5] },
                Point { id: 26, marker: 0, coords: vec![2.5, 1.0] },
                Point { id: 27, marker: 0, coords: vec![2.0, 1.0] },
                Point { id: 28, marker: 0, coords: vec![1.5, 3.0] },
                Point { id: 29, marker: 0, coords: vec![0.0, 3.0] },
                Point { id: 30, marker: 0, coords: vec![1.5, 2.0] },
                Point { id: 31, marker: 0, coords: vec![1.0, 3.0] },
                Point { id: 32, marker: 0, coords: vec![0.0, 2.5] },
                Point { id: 33, marker: 0, coords: vec![1.5, 2.5] },
                Point { id: 34, marker: 0, coords: vec![0.5, 3.0] },
                Point { id: 35, marker: 0, coords: vec![0.0, 2.0] },
                Point { id: 36, marker: 0, coords: vec![0.5, 2.0] },
                Point { id: 37, marker: 0, coords: vec![1.0, 2.0] },
                Point { id: 38, marker: 0, coords: vec![1.0, 2.5] },
                Point { id: 39, marker: 0, coords: vec![0.5, 2.5] },
                Point { id: 40, marker: 0, coords: vec![3.0, 3.0] },
                Point { id: 41, marker: 0, coords: vec![3.0, 2.0] },
                Point { id: 42, marker: 0, coords: vec![2.5, 3.0] },
                Point { id: 43, marker: 0, coords: vec![3.0, 2.5] },
                Point { id: 44, marker: 0, coords: vec![2.0, 3.0] },
                Point { id: 45, marker: 0, coords: vec![2.0, 2.0] },
                Point { id: 46, marker: 0, coords: vec![2.5, 2.0] },
                Point { id: 47, marker: 0, coords: vec![2.5, 2.5] },
                Point { id: 48, marker: 0, coords: vec![2.0, 2.5] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua16, points: vec![0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua16, points: vec![1, 16, 17,  2, 18, 19, 20,  9, 21, 22, 23,  5, 24, 25, 26, 27] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua16, points: vec![3,  2, 28, 29, 10, 30, 31, 32,  6, 33, 34, 35, 36, 37, 38, 39] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua16, points: vec![2, 17, 40, 28, 23, 41, 42, 33, 20, 43, 44, 30, 45, 46, 47, 48] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with four qua17 cells
    ///
    /// ```text
    /// cell ids as in block_2d_four_qua8
    ///
    /// 4.0  30---38---32---37---29---48---43---47---41
    ///       |                   |                   |
    /// 3.5  39                  36                  46
    ///       |                   |                   |
    /// 3.0  33        34        31        44        42
    ///       |                   |                   |
    /// 2.5  40                  35                  45
    ///       |                   |                   |
    /// 2.0   3---14----6---13----2---28---21---27---18
    ///       |                   |                   |
    /// 1.5  15                  12                  26
    ///       |                   |                   |
    /// 1.0   7         8         5        22        20
    ///       |                   |                   |
    /// 0.5  16                  11                  25
    ///       |                   |                   |
    /// 0.0   0----9----4---10----1---23---19---24---17
    ///
    ///      0.0  0.5  1.0  1.5  2.0  2.5  3.0  3.5  4.0
    ///
    /// xmin = 0.0, xmax = 4.0
    /// ymin = 0.0, ymax = 4.0
    /// ```
    ///
    /// ![block_2d_four_qua17](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_2d_four_qua17.svg)
    #[rustfmt::skip]
    pub fn block_2d_four_qua17() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![2.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![2.0, 2.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 2.0] },
                Point { id:  4, marker: 0, coords: vec![1.0, 0.0] },
                Point { id:  5, marker: 0, coords: vec![2.0, 1.0] },
                Point { id:  6, marker: 0, coords: vec![1.0, 2.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0] },
                Point { id:  8, marker: 0, coords: vec![1.0, 1.0] },
                Point { id:  9, marker: 0, coords: vec![0.5, 0.0] },
                Point { id: 10, marker: 0, coords: vec![1.5, 0.0] },
                Point { id: 11, marker: 0, coords: vec![2.0, 0.5] },
                Point { id: 12, marker: 0, coords: vec![2.0, 1.5] },
                Point { id: 13, marker: 0, coords: vec![1.5, 2.0] },
                Point { id: 14, marker: 0, coords: vec![0.5, 2.0] },
                Point { id: 15, marker: 0, coords: vec![0.0, 1.5] },
                Point { id: 16, marker: 0, coords: vec![0.0, 0.5] },
                Point { id: 17, marker: 0, coords: vec![4.0, 0.0] },
                Point { id: 18, marker: 0, coords: vec![4.0, 2.0] },
                Point { id: 19, marker: 0, coords: vec![3.0, 0.0] },
                Point { id: 20, marker: 0, coords: vec![4.0, 1.0] },
                Point { id: 21, marker: 0, coords: vec![3.0, 2.0] },
                Point { id: 22, marker: 0, coords: vec![3.0, 1.0] },
                Point { id: 23, marker: 0, coords: vec![2.5, 0.0] },
                Point { id: 24, marker: 0, coords: vec![3.5, 0.0] },
                Point { id: 25, marker: 0, coords: vec![4.0, 0.5] },
                Point { id: 26, marker: 0, coords: vec![4.0, 1.5] },
                Point { id: 27, marker: 0, coords: vec![3.5, 2.0] },
                Point { id: 28, marker: 0, coords: vec![2.5, 2.0] },
                Point { id: 29, marker: 0, coords: vec![2.0, 4.0] },
                Point { id: 30, marker: 0, coords: vec![0.0, 4.0] },
                Point { id: 31, marker: 0, coords: vec![2.0, 3.0] },
                Point { id: 32, marker: 0, coords: vec![1.0, 4.0] },
                Point { id: 33, marker: 0, coords: vec![0.0, 3.0] },
                Point { id: 34, marker: 0, coords: vec![1.0, 3.0] },
                Point { id: 35, marker: 0, coords: vec![2.0, 2.5] },
                Point { id: 36, marker: 0, coords: vec![2.0, 3.5] },
                Point { id: 37, marker: 0, coords: vec![1.5, 4.0] },
                Point { id: 38, marker: 0, coords: vec![0.5, 4.0] },
                Point { id: 39, marker: 0, coords: vec![0.0, 3.5] },
                Point { id: 40, marker: 0, coords: vec![0.0, 2.5] },
                Point { id: 41, marker: 0, coords: vec![4.0, 4.0] },
                Point { id: 42, marker: 0, coords: vec![4.0, 3.0] },
                Point { id: 43, marker: 0, coords: vec![3.0, 4.0] },
                Point { id: 44, marker: 0, coords: vec![3.0, 3.0] },
                Point { id: 45, marker: 0, coords: vec![4.0, 2.5] },
                Point { id: 46, marker: 0, coords: vec![4.0, 3.5] },
                Point { id: 47, marker: 0, coords: vec![3.5, 4.0] },
                Point { id: 48, marker: 0, coords: vec![2.5, 4.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua17, points: vec![0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua17, points: vec![1, 17, 18,  2, 19, 20, 21,  5, 22, 23, 24, 25, 26, 27, 28, 12, 11] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua17, points: vec![3,  2, 29, 30,  6, 31, 32, 33, 34, 14, 13, 35, 36, 37, 38, 39, 40] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua17, points: vec![2, 18, 41, 29, 21, 42, 43, 31, 44, 28, 27, 45, 46, 47, 48, 36, 35] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh with eight hex8 cells
    ///
    /// ```text
    /// Face markers:
    ///  -100 on the -X faces
    ///  -200 on the +X faces
    ///  -300 on the -Y faces
    ///  -400 on the +Y faces
    ///  -500 on the -Z faces
    ///  -600 on the +Z faces
    ///
    ///               z
    ///               |       -1                 -1
    ///              18------------------21------------------25
    ///              /.                  /.                  /|
    ///             / .                 / .                 / |
    ///            /  .                /  .             -2 /  |
    ///           /   .               /   .               /   |
    ///          /    .              /    .              /    |
    ///        19------------------20------------------24     |
    ///        /.     .            /.     .            /|     |
    ///       / .     .           / .     .           / |     |-3
    ///      /  .     .          /  .     .       -2 /  |     |
    ///     /   .     .         /   .     .         /   |     |
    ///    /    .     .        /    .     .        /    |     |
    ///  22==================23==================26     |     |
    ///   |     .     .       |     .     .       |     |     |
    ///   |     .     .       |     .     .       |     |     |
    ///   |     .     4 - - - | - - . - - 7 - - - | - - | - -15
    ///   |     .    /.       |     .    /.       |     |    /|
    ///   |     .   / .       |     .   / .       |     |   / |
    ///   |     .  /  .       |     .  /  .       |     |  /  |
    ///   |     . /   .       |     . /   .       |     | /   |
    ///   |     ./    .       |     ./    .       |     |/    |
    ///   |     5 - - - - - - | - - 6 - - - - - - | - -14     |
    ///   |    /.     .       |    /.     .       |    /|     |-3
    ///   |   / .     .       |   / .     .       |   / |     |
    ///   |  /  .     .       |  /  .     .       |  /  |     |
    ///   | /   .     .       | /   .     .       | /   |     |
    ///   |/    .     .       |/    .     .       |/    |     |
    ///  10==================11==================17     |     |
    ///   |     .     .       |     .     .       |     |     |
    ///   |     .     .       |     .     .       |     |     |
    ///   |     .     0 - - - | - - . - - 3 - - - | - - | - -13 ---> y
    ///   |     .    /        |     .    /        |     |    /
    ///   |     .   /         |     .   /         |     |   /
    ///   |     .  /          |     .  /          |     |  /
    ///   |     . /           |     . /           |     | /
    ///   |     ./            |     ./            |     |/
    ///   |     1 - - - - - - | - - 2 - - - - - - | - -12
    ///   |    /              |    /              |    /
    ///   |   /               |   /               |   /
    ///   |  /                |  /                |  /
    ///   | /                 | /                 | /
    ///   |/                  |/                  |/
    ///   8===================9==================16
    ///  /        -4                   -4
    /// x
    ///
    /// xmin = 0.0, xmax = 2.0
    /// ymin = 0.0, ymax = 2.0
    /// zmin = 0.0, zmax = 4.0
    /// ```
    ///
    /// ![block_3d_eight_hex8](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_3d_eight_hex8.svg)
    #[rustfmt::skip]
    pub fn block_3d_eight_hex8() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.0, 0.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.0, 1.0, 0.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id:  4, marker: 0, coords: vec![0.0, 0.0, 2.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.0, 2.0] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.0, 2.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0, 2.0] },
                Point { id:  8, marker: 0, coords: vec![2.0, 0.0, 0.0] },
                Point { id:  9, marker: 0, coords: vec![2.0, 1.0, 0.0] },
                Point { id: 10, marker: 0, coords: vec![2.0, 0.0, 2.0] },
                Point { id: 11, marker: 0, coords: vec![2.0, 1.0, 2.0] },
                Point { id: 12, marker: 0, coords: vec![1.0, 2.0, 0.0] },
                Point { id: 13, marker: 0, coords: vec![0.0, 2.0, 0.0] },
                Point { id: 14, marker: 0, coords: vec![1.0, 2.0, 2.0] },
                Point { id: 15, marker: 0, coords: vec![0.0, 2.0, 2.0] },
                Point { id: 16, marker: 0, coords: vec![2.0, 2.0, 0.0] },
                Point { id: 17, marker: 0, coords: vec![2.0, 2.0, 2.0] },
                Point { id: 18, marker: 0, coords: vec![0.0, 0.0, 4.0] },
                Point { id: 19, marker: 0, coords: vec![1.0, 0.0, 4.0] },
                Point { id: 20, marker: 0, coords: vec![1.0, 1.0, 4.0] },
                Point { id: 21, marker: 0, coords: vec![0.0, 1.0, 4.0] },
                Point { id: 22, marker: 0, coords: vec![2.0, 0.0, 4.0] },
                Point { id: 23, marker: 0, coords: vec![2.0, 1.0, 4.0] },
                Point { id: 24, marker: 0, coords: vec![1.0, 2.0, 4.0] },
                Point { id: 25, marker: 0, coords: vec![0.0, 2.0, 4.0] },
                Point { id: 26, marker: 0, coords: vec![2.0, 2.0, 4.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex8, points: vec![0,  1,  2,  3,  4,  5,  6,  7] },
                Cell { id: 1, marker: 1, kind: GeoKind::Hex8, points: vec![1,  8,  9,  2,  5, 10, 11,  6] },
                Cell { id: 2, marker: 1, kind: GeoKind::Hex8, points: vec![3,  2, 12, 13,  7,  6, 14, 15] },
                Cell { id: 3, marker: 1, kind: GeoKind::Hex8, points: vec![2,  9, 16, 12,  6, 11, 17, 14] },
                Cell { id: 4, marker: 1, kind: GeoKind::Hex8, points: vec![4,  5,  6,  7, 18, 19, 20, 21] },
                Cell { id: 5, marker: 1, kind: GeoKind::Hex8, points: vec![5, 10, 11,  6, 19, 22, 23, 20] },
                Cell { id: 6, marker: 1, kind: GeoKind::Hex8, points: vec![7,  6, 14, 15, 21, 20, 24, 25] },
                Cell { id: 7, marker: 1, kind: GeoKind::Hex8, points: vec![6, 11, 17, 14, 20, 23, 26, 24] },
            ],
            marked_edges: vec![
                (-4,  8,  9),
                (-3, 13, 15),
                (-4,  9, 16),
                (-1, 18, 21),
                (-2, 24, 25),
                (-1, 21, 25),
                (-3, 15, 25),
                (-2, 24, 26),
            ],
            marked_faces: vec![
                (-100,  0,  3,  4,  7),
                (-300,  0,  1,  4,  5),
                (-500,  0,  1,  2,  3),
                //
                (-200,  8,  9, 10, 11),
                (-300,  1,  5,  8, 10),
                (-500,  1,  2,  8,  9),
                //
                (-100,  3,  7, 13, 15),
                (-400, 12, 13, 14, 15),
                (-500,  2,  3, 12, 13),
                //
                (-200,  9, 11, 16, 17),
                (-400, 12, 14, 16, 17),
                (-500,  2,  9, 12, 16),
                //
                (-100,  4,  7, 18, 21),
                (-300,  4,  5, 18, 19),
                (-600, 18, 19, 20, 21),
                //
                (-200, 10, 11, 22, 23),
                (-300,  5, 10, 19, 22),
                (-600, 19, 20, 22, 23),
                //
                (-100,  7, 15, 21, 25),
                (-400, 14, 15, 24, 25),
                (-600, 20, 21, 24, 25),
                //
                (-200, 11, 17, 23, 26),
                (-400, 14, 17, 24, 26),
                (-600, 20, 23, 24, 26),
            ]
        }
    }

    /// Returns a mesh with eight hex20 cells
    ///
    /// ```text
    ///              51--------58--------54--------74--------71
    ///              /.                  /.                  /|
    ///             / .                 / .                 / |
    ///           55  .               57  .               73  |
    ///           /   .               /   .               /   |
    ///          /    .              /    .              /    |
    ///        52--------56--------53--------72--------70     |
    ///        /.     .            /.     .            /|     |
    ///       / .    59           / .    62           / |    76
    ///     65  .     .         67  .     .         79  |     |
    ///     /   .     .         /   .     .         /   |     |
    ///    /    .     .        /    .     .        /    |     |
    ///  63========66========64========78========77     |     |
    ///   |     .     .       |     .     .       |     |     |
    ///   |    60     .       |    61     .       |    75     |
    ///   |     .     4 - - - |15 - . - - 7 - - - |41 - | - -35
    ///   |     .    /.       |     .    /.       |     |    /|
    ///   |     .   / .       |     .   / .       |     |   / |
    ///   |     . 12  .       |     . 14  .       |     | 40  |
    ///   |     . /   .       |     . /   .       |     | /   |
    ///  68     ./    .      69     ./    .      80     |/    |
    ///   |     5 - - - -13 - | - - 6 - - - -39 - | - -34     |
    ///   |    /.     .       |    /.     .       |    /|     |
    ///   |   / .    16       |   / .    19       |   / |    43
    ///   | 27  .     .       | 29  .     .       | 49  |     |
    ///   | /   .     .       | /   .     .       | /   |     |
    ///   |/    .     .       |/    .     .       |/    |     |
    ///  22========28========23========48========45     |     |
    ///   |     .     .       |     .     .       |     |     |
    ///   |    17     .       |    18     .       |    42     |
    ///   |     .     0 - - - |11 - . - - 3 - - - |38 - | - -33
    ///   |     .    /        |     .    /        |     |    /
    ///   |     .   /         |     .   /         |     |   /
    ///   |     .  8          |     . 10          |     | 37
    ///   |     . /           |     . /           |     | /
    ///  30     ./           31     ./           50     |/
    ///   |     1 - - - - 9 - | - - 2 - - - -36 - | - -32
    ///   |    /              |    /              |    /
    ///   |   /               |   /               |   /
    ///   | 24                | 26                | 47
    ///   | /                 | /                 | /
    ///   |/                  |/                  |/
    ///  20========25========21========46========44
    ///
    /// xmin = 0.0, xmax = 2.0
    /// ymin = 0.0, ymax = 2.0
    /// zmin = 0.0, zmax = 4.0
    /// ```
    ///
    /// ![block_3d_eight_hex20](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_block_3d_eight_hex20.svg)
    #[rustfmt::skip]
    pub fn block_3d_eight_hex20() -> Mesh {
        Mesh {
            ndim: 3,
            points: vec![
                Point { id:  0, marker: 0, coords: vec![0.0, 0.0, 0.0] },
                Point { id:  1, marker: 0, coords: vec![1.0, 0.0, 0.0] },
                Point { id:  2, marker: 0, coords: vec![1.0, 1.0, 0.0] },
                Point { id:  3, marker: 0, coords: vec![0.0, 1.0, 0.0] },
                Point { id:  4, marker: 0, coords: vec![0.0, 0.0, 2.0] },
                Point { id:  5, marker: 0, coords: vec![1.0, 0.0, 2.0] },
                Point { id:  6, marker: 0, coords: vec![1.0, 1.0, 2.0] },
                Point { id:  7, marker: 0, coords: vec![0.0, 1.0, 2.0] },
                Point { id:  8, marker: 0, coords: vec![0.5, 0.0, 0.0] },
                Point { id:  9, marker: 0, coords: vec![1.0, 0.5, 0.0] },
                Point { id: 10, marker: 0, coords: vec![0.5, 1.0, 0.0] },
                Point { id: 11, marker: 0, coords: vec![0.0, 0.5, 0.0] },
                Point { id: 12, marker: 0, coords: vec![0.5, 0.0, 2.0] },
                Point { id: 13, marker: 0, coords: vec![1.0, 0.5, 2.0] },
                Point { id: 14, marker: 0, coords: vec![0.5, 1.0, 2.0] },
                Point { id: 15, marker: 0, coords: vec![0.0, 0.5, 2.0] },
                Point { id: 16, marker: 0, coords: vec![0.0, 0.0, 1.0] },
                Point { id: 17, marker: 0, coords: vec![1.0, 0.0, 1.0] },
                Point { id: 18, marker: 0, coords: vec![1.0, 1.0, 1.0] },
                Point { id: 19, marker: 0, coords: vec![0.0, 1.0, 1.0] },
                Point { id: 20, marker: 0, coords: vec![2.0, 0.0, 0.0] },
                Point { id: 21, marker: 0, coords: vec![2.0, 1.0, 0.0] },
                Point { id: 22, marker: 0, coords: vec![2.0, 0.0, 2.0] },
                Point { id: 23, marker: 0, coords: vec![2.0, 1.0, 2.0] },
                Point { id: 24, marker: 0, coords: vec![1.5, 0.0, 0.0] },
                Point { id: 25, marker: 0, coords: vec![2.0, 0.5, 0.0] },
                Point { id: 26, marker: 0, coords: vec![1.5, 1.0, 0.0] },
                Point { id: 27, marker: 0, coords: vec![1.5, 0.0, 2.0] },
                Point { id: 28, marker: 0, coords: vec![2.0, 0.5, 2.0] },
                Point { id: 29, marker: 0, coords: vec![1.5, 1.0, 2.0] },
                Point { id: 30, marker: 0, coords: vec![2.0, 0.0, 1.0] },
                Point { id: 31, marker: 0, coords: vec![2.0, 1.0, 1.0] },
                Point { id: 32, marker: 0, coords: vec![1.0, 2.0, 0.0] },
                Point { id: 33, marker: 0, coords: vec![0.0, 2.0, 0.0] },
                Point { id: 34, marker: 0, coords: vec![1.0, 2.0, 2.0] },
                Point { id: 35, marker: 0, coords: vec![0.0, 2.0, 2.0] },
                Point { id: 36, marker: 0, coords: vec![1.0, 1.5, 0.0] },
                Point { id: 37, marker: 0, coords: vec![0.5, 2.0, 0.0] },
                Point { id: 38, marker: 0, coords: vec![0.0, 1.5, 0.0] },
                Point { id: 39, marker: 0, coords: vec![1.0, 1.5, 2.0] },
                Point { id: 40, marker: 0, coords: vec![0.5, 2.0, 2.0] },
                Point { id: 41, marker: 0, coords: vec![0.0, 1.5, 2.0] },
                Point { id: 42, marker: 0, coords: vec![1.0, 2.0, 1.0] },
                Point { id: 43, marker: 0, coords: vec![0.0, 2.0, 1.0] },
                Point { id: 44, marker: 0, coords: vec![2.0, 2.0, 0.0] },
                Point { id: 45, marker: 0, coords: vec![2.0, 2.0, 2.0] },
                Point { id: 46, marker: 0, coords: vec![2.0, 1.5, 0.0] },
                Point { id: 47, marker: 0, coords: vec![1.5, 2.0, 0.0] },
                Point { id: 48, marker: 0, coords: vec![2.0, 1.5, 2.0] },
                Point { id: 49, marker: 0, coords: vec![1.5, 2.0, 2.0] },
                Point { id: 50, marker: 0, coords: vec![2.0, 2.0, 1.0] },
                Point { id: 51, marker: 0, coords: vec![0.0, 0.0, 4.0] },
                Point { id: 52, marker: 0, coords: vec![1.0, 0.0, 4.0] },
                Point { id: 53, marker: 0, coords: vec![1.0, 1.0, 4.0] },
                Point { id: 54, marker: 0, coords: vec![0.0, 1.0, 4.0] },
                Point { id: 55, marker: 0, coords: vec![0.5, 0.0, 4.0] },
                Point { id: 56, marker: 0, coords: vec![1.0, 0.5, 4.0] },
                Point { id: 57, marker: 0, coords: vec![0.5, 1.0, 4.0] },
                Point { id: 58, marker: 0, coords: vec![0.0, 0.5, 4.0] },
                Point { id: 59, marker: 0, coords: vec![0.0, 0.0, 3.0] },
                Point { id: 60, marker: 0, coords: vec![1.0, 0.0, 3.0] },
                Point { id: 61, marker: 0, coords: vec![1.0, 1.0, 3.0] },
                Point { id: 62, marker: 0, coords: vec![0.0, 1.0, 3.0] },
                Point { id: 63, marker: 0, coords: vec![2.0, 0.0, 4.0] },
                Point { id: 64, marker: 0, coords: vec![2.0, 1.0, 4.0] },
                Point { id: 65, marker: 0, coords: vec![1.5, 0.0, 4.0] },
                Point { id: 66, marker: 0, coords: vec![2.0, 0.5, 4.0] },
                Point { id: 67, marker: 0, coords: vec![1.5, 1.0, 4.0] },
                Point { id: 68, marker: 0, coords: vec![2.0, 0.0, 3.0] },
                Point { id: 69, marker: 0, coords: vec![2.0, 1.0, 3.0] },
                Point { id: 70, marker: 0, coords: vec![1.0, 2.0, 4.0] },
                Point { id: 71, marker: 0, coords: vec![0.0, 2.0, 4.0] },
                Point { id: 72, marker: 0, coords: vec![1.0, 1.5, 4.0] },
                Point { id: 73, marker: 0, coords: vec![0.5, 2.0, 4.0] },
                Point { id: 74, marker: 0, coords: vec![0.0, 1.5, 4.0] },
                Point { id: 75, marker: 0, coords: vec![1.0, 2.0, 3.0] },
                Point { id: 76, marker: 0, coords: vec![0.0, 2.0, 3.0] },
                Point { id: 77, marker: 0, coords: vec![2.0, 2.0, 4.0] },
                Point { id: 78, marker: 0, coords: vec![2.0, 1.5, 4.0] },
                Point { id: 79, marker: 0, coords: vec![1.5, 2.0, 4.0] },
                Point { id: 80, marker: 0, coords: vec![2.0, 2.0, 3.0] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Hex20, points: vec![0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19] },
                Cell { id: 1, marker: 1, kind: GeoKind::Hex20, points: vec![1, 20, 21,  2,  5, 22, 23,  6, 24, 25, 26,  9, 27, 28, 29, 13, 17, 30, 31, 18] },
                Cell { id: 2, marker: 1, kind: GeoKind::Hex20, points: vec![3,  2, 32, 33,  7,  6, 34, 35, 10, 36, 37, 38, 14, 39, 40, 41, 19, 18, 42, 43] },
                Cell { id: 3, marker: 1, kind: GeoKind::Hex20, points: vec![2, 21, 44, 32,  6, 23, 45, 34, 26, 46, 47, 36, 29, 48, 49, 39, 18, 31, 50, 42] },
                Cell { id: 4, marker: 1, kind: GeoKind::Hex20, points: vec![4,  5,  6,  7, 51, 52, 53, 54, 12, 13, 14, 15, 55, 56, 57, 58, 59, 60, 61, 62] },
                Cell { id: 5, marker: 1, kind: GeoKind::Hex20, points: vec![5, 22, 23,  6, 52, 63, 64, 53, 27, 28, 29, 13, 65, 66, 67, 56, 60, 68, 69, 61] },
                Cell { id: 6, marker: 1, kind: GeoKind::Hex20, points: vec![7,  6, 34, 35, 54, 53, 70, 71, 14, 39, 40, 41, 57, 72, 73, 74, 62, 61, 75, 76] },
                Cell { id: 7, marker: 1, kind: GeoKind::Hex20, points: vec![6, 23, 45, 34, 53, 64, 77, 70, 29, 48, 49, 39, 67, 78, 79, 72, 61, 69, 80, 75] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh of a quarter of a ring with eight Qua8 (radius=1)
    ///
    /// ```text
    /// 2.0   14---36--,__11
    ///        |          `,-..33
    /// 1.75  24   [7]   22     `-,
    ///        |         ,  [5]    ,8.
    /// 1.5   13--35--10/        20   `*
    ///        |       ,`*32    ,'      30
    /// 1.25  23 [6] 21     *.7     [3]   *
    ///        |     ,  [4]  , *.          5
    /// 1.0   12-34-9      19    29     18' *
    ///              `31. ,' [2]   *  _,     *
    ///                  6.       _.4'        *
    ///                   28  _.17   *   [1]  27
    ///                     3'  [0]  26        *
    ///                     25        *        *
    ///        +             0---15---1---16---2
    ///
    ///                     1.0 1.25  1.5 1.75  2.0
    /// ```
    ///
    /// ```text
    ///  -3 =---__     point markers        -3 =---__     edge markers
    ///   |        '*._                      |        '*._
    ///   | -40        *._                   | -400       *._
    ///   |               *.  -20            |               *.  -200
    ///  -4 ==-__           *.              -4 ==-__           *.
    ///          '-.          *                     '-.          *
    ///             *.         *                       *.         *
    ///          -10  *         *                  -100  *         *
    ///                *         *                        *         *
    ///                 *         *                        *         *
    ///                 #   -30   #                        #  -300   #
    ///                -1 ------- -2                      -1 ------- -2
    /// ```
    ///
    /// ![ring_eight_qua8_rad1_thick1](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_ring_eight_qua8_rad1_thick1.svg)
    #[rustfmt::skip]
    pub fn ring_eight_qua8_rad1_thick1() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id:  0, marker:  -1, coords: vec![1.000000000000000e+00, 0.000000000000000e+00] },
                Point { id:  1, marker: -30, coords: vec![1.500000000000000e+00, 0.000000000000000e+00] },
                Point { id:  2, marker:  -2, coords: vec![2.000000000000000e+00, 0.000000000000000e+00] },
                Point { id:  3, marker: -10, coords: vec![9.127002149692066e-01, 4.086298050744269e-01] },
                Point { id:  4, marker:   0, coords: vec![1.357995128834866e+00, 6.079951288348657e-01] },
                Point { id:  5, marker: -20, coords: vec![1.825400429938413e+00, 8.172596101488537e-01] },
                Point { id:  6, marker: -10, coords: vec![7.071067811865476e-01, 7.071067811865475e-01] },
                Point { id:  7, marker:   0, coords: vec![1.060660171779821e+00, 1.060660171779821e+00] },
                Point { id:  8, marker: -20, coords: vec![1.414213562373095e+00, 1.414213562373095e+00] },
                Point { id:  9, marker: -10, coords: vec![4.086298050744270e-01, 9.127002149692066e-01] },
                Point { id: 10, marker:   0, coords: vec![6.079951288348662e-01, 1.357995128834866e+00] },
                Point { id: 11, marker: -20, coords: vec![8.172596101488541e-01, 1.825400429938413e+00] },
                Point { id: 12, marker:  -4, coords: vec![6.123233995736766e-17, 1.000000000000000e+00] },
                Point { id: 13, marker: -40, coords: vec![9.184850993605148e-17, 1.500000000000000e+00] },
                Point { id: 14, marker:  -3, coords: vec![1.224646799147353e-16, 2.000000000000000e+00] },
                Point { id: 15, marker: -30, coords: vec![1.250000000000000e+00, 0.000000000000000e+00] },
                Point { id: 16, marker: -30, coords: vec![1.750000000000000e+00, 0.000000000000000e+00] },
                Point { id: 17, marker:   0, coords: vec![1.131662607362388e+00, 5.066626073623883e-01] },
                Point { id: 18, marker:   0, coords: vec![1.584327650307344e+00, 7.093276503073436e-01] },
                Point { id: 19, marker:   0, coords: vec![8.838834764831844e-01, 8.838834764831842e-01] },
                Point { id: 20, marker:   0, coords: vec![1.237436867076458e+00, 1.237436867076458e+00] },
                Point { id: 21, marker:   0, coords: vec![5.066626073623884e-01, 1.131662607362388e+00] },
                Point { id: 22, marker:   0, coords: vec![7.093276503073440e-01, 1.584327650307344e+00] },
                Point { id: 23, marker: -40, coords: vec![7.654042494670958e-17, 1.250000000000000e+00] },
                Point { id: 24, marker: -40, coords: vec![1.071565949253934e-16, 1.750000000000000e+00] },
                Point { id: 25, marker: -10, coords: vec![9.759662299218728e-01, 2.179218163747866e-01] },
                Point { id: 26, marker:   0, coords: vec![1.448413825153672e+00, 3.234138251536718e-01] },
                Point { id: 27, marker: -20, coords: vec![1.951932459843746e+00, 4.358436327495732e-01] },
                Point { id: 28, marker: -10, coords: vec![8.212291819630956e-01, 5.705984846564395e-01] },
                Point { id: 29, marker:   0, coords: vec![1.228743911043582e+00, 8.537439110435825e-01] },
                Point { id: 30, marker: -20, coords: vec![1.642458363926191e+00, 1.141196969312879e+00] },
                Point { id: 31, marker: -10, coords: vec![5.705984846564395e-01, 8.212291819630954e-01] },
                Point { id: 32, marker:   0, coords: vec![8.537439110435825e-01, 1.228743911043582e+00] },
                Point { id: 33, marker: -20, coords: vec![1.141196969312879e+00, 1.642458363926191e+00] },
                Point { id: 34, marker: -10, coords: vec![2.179218163747867e-01, 9.759662299218727e-01] },
                Point { id: 35, marker:   0, coords: vec![3.234138251536719e-01, 1.448413825153672e+00] },
                Point { id: 36, marker: -20, coords: vec![4.358436327495734e-01, 1.951932459843745e+00] },
            ],
            cells: vec![
                Cell { id: 0, marker: 1, kind: GeoKind::Qua8, points: vec![ 0, 1, 4, 3,15,26,17,25] },
                Cell { id: 1, marker: 1, kind: GeoKind::Qua8, points: vec![ 1, 2, 5, 4,16,27,18,26] },
                Cell { id: 2, marker: 1, kind: GeoKind::Qua8, points: vec![ 3, 4, 7, 6,17,29,19,28] },
                Cell { id: 3, marker: 1, kind: GeoKind::Qua8, points: vec![ 4, 5, 8, 7,18,30,20,29] },
                Cell { id: 4, marker: 1, kind: GeoKind::Qua8, points: vec![ 6, 7,10, 9,19,32,21,31] },
                Cell { id: 5, marker: 1, kind: GeoKind::Qua8, points: vec![ 7, 8,11,10,20,33,22,32] },
                Cell { id: 6, marker: 1, kind: GeoKind::Qua8, points: vec![ 9,10,13,12,21,35,23,34] },
                Cell { id: 7, marker: 1, kind: GeoKind::Qua8, points: vec![10,11,14,13,22,36,24,35] },
            ],
            marked_edges: vec![
                (-100, 12,  9), (-100,  9,  6), (-100, 6, 3), (-100, 3, 0),
                (-200, 14, 11), (-200, 11,  8), (-200, 8, 5), (-200, 5, 2),
                (-300,  0,  1), (-300,  1,  2),
                (-400, 12, 13), (-400, 13, 14)
            ],
            marked_faces: Vec::new(),
        }
    }

    /// Returns a mesh of resulting from a Delaunay triangulations
    ///
    /// ![tri3_from_delaunay](https://raw.githubusercontent.com/cpmech/gemlab/main/data/figures/test_mesh_tri3_from_delaunay.svg)
    #[rustfmt::skip]
    pub fn tri3_from_delaunay() -> Mesh {
        Mesh {
            ndim: 2,
            points: vec![
                Point { id: 0, marker: 0, coords: vec![0.0307942, 0.459123  ] },
                Point { id: 1, marker: 0, coords: vec![0.0980015, 0.981755  ] },
                Point { id: 2, marker: 0, coords: vec![0.133721,  0.348832  ] },
                Point { id: 3, marker: 0, coords: vec![0.13928,   0.180603  ] },
                Point { id: 4, marker: 0, coords: vec![0.230951,  0.558482  ] },
                Point { id: 5, marker: 0, coords: vec![0.478554,  0.00869692] },
                Point { id: 6, marker: 0, coords: vec![0.540745,  0.331184  ] },
                Point { id: 7, marker: 0, coords: vec![0.578587,  0.760349  ] },
                Point { id: 8, marker: 0, coords: vec![0.648071,  0.369534  ] },
                Point { id: 9, marker: 0, coords: vec![0.903726,  0.975904  ] },
            ],
            cells: vec![
                Cell { id:  0, marker: 1, kind: GeoKind::Tri3, points: vec![4, 2, 6] },
                Cell { id:  1, marker: 1, kind: GeoKind::Tri3, points: vec![3, 2, 0] },
                Cell { id:  2, marker: 1, kind: GeoKind::Tri3, points: vec![0, 4, 1] }, // << large on y
                Cell { id:  3, marker: 1, kind: GeoKind::Tri3, points: vec![4, 0, 2] },
                Cell { id:  4, marker: 1, kind: GeoKind::Tri3, points: vec![1, 4, 7] },
                Cell { id:  5, marker: 1, kind: GeoKind::Tri3, points: vec![2, 3, 6] },
                Cell { id:  6, marker: 1, kind: GeoKind::Tri3, points: vec![6, 7, 4] },
                Cell { id:  7, marker: 1, kind: GeoKind::Tri3, points: vec![6, 5, 8] },
                Cell { id:  8, marker: 1, kind: GeoKind::Tri3, points: vec![7, 8, 9] }, // << very large
                Cell { id:  9, marker: 1, kind: GeoKind::Tri3, points: vec![8, 7, 6] },
                Cell { id: 10, marker: 1, kind: GeoKind::Tri3, points: vec![7, 9, 1] }, // << very large
                Cell { id: 11, marker: 1, kind: GeoKind::Tri3, points: vec![6, 3, 5] },
            ],
            marked_edges: Vec::new(),
            marked_faces: Vec::new(),
        }
    }
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

#[cfg(test)]
mod tests {
    use super::Samples;
    use crate::mesh::{Draw, Mesh};

    const SAVE_FIGURE: bool = false;

    fn draw(mesh: &Mesh, larger: bool, filename: &str) {
        let mut draw = Draw::new();
        draw.show_cell_ids(true).show_point_ids(true);
        if larger {
            draw.set_size(600.0, 600.0);
        }
        draw.all(&mesh, filename).unwrap();
    }

    #[test]
    fn samples_work() {
        let mesh = Samples::lin_cells();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 14);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();

        let mesh = Samples::lin_cells_3d();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 14);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();

        let mesh = Samples::tri_cells();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 34);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();

        let mesh = Samples::qua_cells();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 66);
        assert_eq!(mesh.cells.len(), 6);
        mesh.check_all().unwrap();

        let mesh = Samples::tet_cells();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 34);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();

        let mesh = Samples::hex_cells();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 60);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();

        let mesh = Samples::one_lin2();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 2);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_lin2.svg");
        }

        let mesh = Samples::graph_8_edges();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 8);
        assert_eq!(mesh.cells.len(), 8);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_graph_8_edges.svg");
        }

        let mesh = Samples::graph_12_edges();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 9);
        assert_eq!(mesh.cells.len(), 12);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_graph_12_edges.svg");
        }

        let mesh = Samples::one_tri3();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 3);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_tri3.svg");
        }

        let mesh = Samples::one_tri6();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 6);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_tri6.svg");
        }

        let mesh = Samples::one_qua4();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 4);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_qua4.svg");
        }

        let mesh = Samples::two_tri3();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 4);
        assert_eq!(mesh.cells.len(), 2);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_two_tri3.svg");
        }

        let mesh = Samples::tri3_qua4_lin2();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 6);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_tri3_qua4_lin2.svg");
        }

        let mesh = Samples::three_tri3();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 5);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_three_tri3.svg");
        }

        let mesh = Samples::three_tri3_arrow();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 4);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_three_tri3_arrow.svg")
        }

        let mesh = Samples::three_tri6_arrow();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 10);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_three_tri6_arrow.svg")
        }

        let mesh = Samples::four_tri3();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 5);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_four_tri3.svg");
        }

        let mesh = Samples::two_tri3_one_qua4();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 6);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_two_tri3_one_qua4.svg");
        }

        let mesh = Samples::one_qua8();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 8);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_qua8.svg");
        }

        let mesh = Samples::two_qua4();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 6);
        assert_eq!(mesh.cells.len(), 2);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_two_qua4.svg");
        }

        let mesh = Samples::qua8_tri6_lin2();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 11);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_qua8_tri6_lin2.svg");
        }

        let mesh = Samples::qua8_tri6_lin2_three_dimensional();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 11);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            let mut draw = Draw::new();
            draw.show_cell_ids(true)
                .show_point_ids(true)
                .set_size(800.0, 800.0)
                .set_view_flag(false)
                .set_camera(30.0, 90.0);
            draw.all(&mesh, "/tmp/gemlab/test_mesh_qua8_tri6_lin2_three_dimensional.svg")
                .unwrap();
        }

        let mesh = Samples::one_tet4();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 4);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_tet4.svg");
        }

        let mesh = Samples::one_tet10(0.0);
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 10);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_tet10.svg");
        }

        let mesh = Samples::one_hex8();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 8);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_hex8.svg");
        }

        let mesh = Samples::two_hex8();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 12);
        assert_eq!(mesh.cells.len(), 2);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_two_hex8.svg");
        }

        let mesh = Samples::four_hex8();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 18);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_four_hex8.svg");
        }

        let mesh = Samples::one_hex20(0.0, 0.0, 0.0);
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 20);
        assert_eq!(mesh.cells.len(), 1);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_one_hex20.svg");
        }

        let mesh = Samples::mixed_shapes_2d();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 6);
        assert_eq!(mesh.cells.len(), 3);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_mixed_shapes_2d.svg");
        }

        let mesh = Samples::mixed_shapes_3d();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 13);
        assert_eq!(mesh.cells.len(), 5);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_mixed_shapes_3d.svg");
        }

        let mesh = Samples::block_2d_four_qua4();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 9);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_block_2d_four_qua4.svg");
        }

        let mesh = Samples::block_2d_four_qua8();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 21);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_block_2d_four_qua8.svg");
        }

        let mesh = Samples::block_2d_four_qua9();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 25);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_block_2d_four_qua9.svg");
        }

        let mesh = Samples::block_2d_four_qua12();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 33);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_block_2d_four_qua12.svg");
        }

        let mesh = Samples::block_2d_four_qua16();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 49);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_block_2d_four_qua16.svg");
        }

        let mesh = Samples::block_2d_four_qua17();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 49);
        assert_eq!(mesh.cells.len(), 4);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_block_2d_four_qua17.svg");
        }

        let mesh = Samples::block_3d_eight_hex8();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 27);
        assert_eq!(mesh.cells.len(), 8);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_block_3d_eight_hex8.svg");
        }

        let mesh = Samples::block_3d_eight_hex20();
        assert_eq!(mesh.ndim, 3);
        assert_eq!(mesh.points.len(), 81);
        assert_eq!(mesh.cells.len(), 8);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_block_3d_eight_hex20.svg");
        }

        let mesh = Samples::ring_eight_qua8_rad1_thick1();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 37);
        assert_eq!(mesh.cells.len(), 8);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, true, "/tmp/gemlab/test_mesh_ring_eight_qua8_rad1_thick1.svg");
        }

        let mesh = Samples::tri3_from_delaunay();
        assert_eq!(mesh.ndim, 2);
        assert_eq!(mesh.points.len(), 10);
        assert_eq!(mesh.cells.len(), 12);
        mesh.check_all().unwrap();
        if SAVE_FIGURE {
            draw(&mesh, false, "/tmp/gemlab/test_mesh_tri3_from_delaunay.svg");
        }
    }
}