How to use pygmsh - 10 common examples

def test(irad=0.05, orad=0.6):
    """Torus, rotated in space.
    """
    geom = pygmsh.built_in.Geometry()

    R = pygmsh.rotation_matrix([1.0, 0.0, 0.0], np.pi / 2)
    geom.add_torus(irad=irad, orad=orad, lcar=0.03, x0=[0.0, 0.0, -1.0], R=R)

    ref = 2 * np.pi ** 2 * orad * irad ** 2
    mesh = pygmsh.generate_mesh(geom)
    assert np.isclose(compute_volume(mesh), ref, rtol=5e-2)
    return mesh

def test():
    x = 5
    y = 4
    z = 3
    x_layers = 10
    y_layers = 5
    z_layers = 3
    geom = pygmsh.built_in.Geometry()
    p = geom.add_point([0, 0, 0], 1)
    _, l, _ = geom.extrude(p, [x, 0, 0], num_layers=x_layers)
    _, s, _ = geom.extrude(l, [0, y, 0], num_layers=y_layers)
    geom.extrude(s, [0, 0, z], num_layers=z_layers)
    mesh = pygmsh.generate_mesh(geom)

    ref_vol = x * y * z
    assert abs(compute_volume(mesh) - ref_vol) < 1.0e-2 * ref_vol

    # Each grid-cell from layered extrusion will result in 6 tetrahedrons.
    ref_tetras = 6 * x_layers * y_layers * z_layers
    assert len(mesh.cells_dict["tetra"]) == ref_tetras

    return mesh

def test(irad=0.05, orad=0.6):
    """Torus, rotated in space.
    """
    geom = pygmsh.built_in.Geometry()

    R = pygmsh.rotation_matrix([1.0, 0.0, 0.0], np.pi / 2)
    geom.add_torus(irad=irad, orad=orad, lcar=0.03, x0=[0.0, 0.0, -1.0], R=R)

    R = pygmsh.rotation_matrix([0.0, 1.0, 0.0], np.pi / 2)
    geom.add_torus(
        irad=irad, orad=orad, lcar=0.03, x0=[0.0, 0.0, 1.0], variant="extrude_circle"
    )

    ref = 2 * 2 * np.pi ** 2 * orad * irad ** 2
    mesh = pygmsh.generate_mesh(geom)
    assert np.isclose(compute_volume(mesh), ref, rtol=5e-2)
    return mesh

def test():
    x = 5
    y = 4
    z = 3
    x_layers = 10
    y_layers = 5
    z_layers = 3
    geom = pygmsh.opencascade.Geometry()
    p = geom.add_point([0, 0, 0], 1)
    _, l, _ = geom.extrude(p, [x, 0, 0], num_layers=x_layers)
    _, s, _ = geom.extrude(l, [0, y, 0], num_layers=y_layers)
    geom.extrude(s, [0, 0, z], num_layers=z_layers)
    mesh = pygmsh.generate_mesh(geom)

    ref_vol = x * y * z
    assert abs(compute_volume(mesh) - ref_vol) < 1.0e-2 * ref_vol

    # Each grid-cell from layered extrusion will result in 6 tetrahedrons.
    ref_tetras = 6 * x_layers * y_layers * z_layers
    assert len(mesh.cells_dict["tetra"]) == ref_tetras

    return mesh

def test():
    geom = pygmsh.opencascade.Geometry()

    geom.add_ellipsoid([1.0, 1.0, 1.0], [1.0, 2.0, 3.0], char_length=0.1)

    ref = 8.0 * pi
    mesh = pygmsh.generate_mesh(geom)
    assert abs(compute_volume(mesh) - ref) < 1.0e-2 * ref
    return mesh

def test():
    # Characteristic length
    lcar = 1e-1

    # Coordinates of lower-left and upper-right vertices of a square domain
    xmin = 0.0
    xmax = 5.0
    ymin = 0.0
    ymax = 5.0

    # Vertices of a square hole
    squareHoleCoordinates = np.array([[1, 1, 0], [4, 1, 0], [4, 4, 0], [1, 4, 0]])

    # Create geometric object
    geom = pygmsh.built_in.Geometry()

    # Create square hole
    squareHole = geom.add_polygon(squareHoleCoordinates, lcar, make_surface=False)

    # Create square domain with square hole
    geom.add_rectangle(xmin, xmax, ymin, ymax, 0.0, lcar, holes=[squareHole.line_loop])

    mesh = pygmsh.generate_mesh(geom, extra_gmsh_arguments=["-order", "2"])
    # TODO support for volumes of triangle6
    # ref = 16.0
    # from helpers import compute_volume
    # assert abs(compute_volume(points, cells) - ref) < 1.0e-2 * ref
    return mesh

def test():
    geom = pygmsh.built_in.Geometry()
    p0 = geom.add_point((0.0, 0.0, 0.0), lcar=1.0)
    p1 = geom.add_point((2.0, 0.0, 0.0), lcar=1.0)
    p2 = geom.add_point((0.0, 1.0, 0.0), lcar=1.0)
    p3 = geom.add_point((2.0, 1.0, 0.0), lcar=1.0)
    l0 = geom.add_line(p0, p1)
    l1 = geom.add_line(p1, p3)
    l2 = geom.add_line(p3, p2)
    l3 = geom.add_line(p2, p0)
    ll0 = geom.add_line_loop((l0, l1, l2, l3))
    rs0 = geom.add_surface(ll0)
    geom.set_transfinite_lines([l3, l1], 3, progression=1)
    geom.set_transfinite_lines([l2, l0], 3, progression=1)
    geom.set_transfinite_surface(rs0)
    geom.set_recombined_surfaces([rs0])

    mesh = pygmsh.generate_mesh(geom)

def test():
    geom = pygmsh.built_in.Geometry()

    lcar = 0.1
    p1 = geom.add_point([0.0, 0.0, 0.0], lcar)
    p2 = geom.add_point([1.0, 0.0, 0.0], lcar)
    p3 = geom.add_point([1.0, 0.5, 0.0], lcar)
    p4 = geom.add_point([1.0, 1.0, 0.0], lcar)
    s1 = geom.add_bspline([p1, p2, p3, p4])

    p2 = geom.add_point([0.0, 1.0, 0.0], lcar)
    p3 = geom.add_point([0.5, 1.0, 0.0], lcar)
    s2 = geom.add_bspline([p4, p3, p2, p1])

    ll = geom.add_line_loop([s1, s2])
    geom.add_plane_surface(ll)

    ref = 0.9156598733673261 if pygmsh.get_gmsh_major_version() < 4 else 0.75

def test():
    x = 5
    y = 4
    z = 3
    x_layers = 10
    y_layers = 5
    z_layers = 3
    geom = pygmsh.built_in.Geometry()
    p = geom.add_point([0, 0, 0], 1)
    _, l, _ = geom.extrude(p, [x, 0, 0], num_layers=x_layers)
    _, s, _ = geom.extrude(l, [0, y, 0], num_layers=y_layers)
    geom.extrude(s, [0, 0, z], num_layers=z_layers)
    mesh = pygmsh.generate_mesh(geom)

    ref_vol = x * y * z
    assert abs(compute_volume(mesh) - ref_vol) < 1.0e-2 * ref_vol

    # Each grid-cell from layered extrusion will result in 6 tetrahedrons.
    ref_tetras = 6 * x_layers * y_layers * z_layers
    assert len(mesh.cells_dict["tetra"]) == ref_tetras

    return mesh

def test(lcar=0.3):
    geom = pygmsh.built_in.Geometry()

    r = 1.25 * 3.4
    p1 = geom.add_point([0.0, 0.0, 0.0], lcar)
    # p2 = geom.add_point([+r, 0.0, 0.0], lcar)
    p3 = geom.add_point([-r, 0.0, 0.0], lcar)
    p4 = geom.add_point([0.0, +r, 0.0], lcar)
    p5 = geom.add_point([0.0, -r, 0.0], lcar)
    p6 = geom.add_point([r * cos(+pi / 12.0), r * sin(+pi / 12.0), 0.0], lcar)
    p7 = geom.add_point([r * cos(-pi / 12.0), r * sin(-pi / 12.0), 0.0], lcar)
    p8 = geom.add_point([0.5 * r, 0.0, 0.0], lcar)

    c0 = geom.add_circle_arc(p6, p1, p4)
    c1 = geom.add_circle_arc(p4, p1, p3)
    c2 = geom.add_circle_arc(p3, p1, p5)
    c3 = geom.add_circle_arc(p5, p1, p7)
    l1 = geom.add_line(p7, p8)