def from_vertices_and_simplices(vertices, simplices, order=1, fix_orientation=False):
"""Imports a mesh from a numpy array of vertices and an array
of simplices.
:arg vertices:
An array of vertex coordinates with shape
*(ambient_dim, nvertices)*
:arg simplices:
An array *(nelements, nvertices)* of (mesh-wide)
vertex indices.
"""
from meshmode.mesh import Mesh
from meshmode.mesh.generation import make_group_from_vertices
grp = make_group_from_vertices(vertices, simplices, order)
if fix_orientation:
if grp.dim != vertices.shape[0]:
raise ValueError("can only fix orientation of volume meshes")
from meshmode.mesh.processing import (
find_volume_mesh_element_group_orientation,
flip_simplex_element_group)
orient = find_volume_mesh_element_group_orientation(vertices, grp)
grp = flip_simplex_element_group(vertices, grp, orient < 0)
return Mesh(
vertices=vertices, groups=[grp],
is_conforming=True)
def from_vertices_and_simplices(vertices, simplices, order=1, fix_orientation=False):
"""Imports a mesh from a numpy array of vertices and an array
of simplices.
:arg vertices:
An array of vertex coordinates with shape
*(ambient_dim, nvertices)*
:arg simplices:
An array *(nelements, nvertices)* of (mesh-wide)
vertex indices.
"""
from meshmode.mesh import Mesh
from meshmode.mesh.generation import make_group_from_vertices
grp = make_group_from_vertices(vertices, simplices, order)
if fix_orientation:
if grp.dim != vertices.shape[0]:
raise ValueError("can only fix orientation of volume meshes")
from meshmode.mesh.processing import (
find_volume_mesh_element_group_orientation,
flip_simplex_element_group)
orient = find_volume_mesh_element_group_orientation(vertices, grp)
grp = flip_simplex_element_group(vertices, grp, orient < 0)
return Mesh(
vertices=vertices, groups=[grp],
is_conforming=True)
def from_vertices_and_simplices(vertices,
simplices,
order=1,
fix_orientation=False):
"""Imports a mesh from a numpy array of vertices and an array
of simplices.
:arg vertices:
An array of vertex coordinates with shape
*(ambient_dim, nvertices)*
:arg simplices:
An array *(nelements, nvertices)* of (mesh-wide)
vertex indices.
"""
from meshmode.mesh import Mesh
from meshmode.mesh.generation import make_group_from_vertices
grp = make_group_from_vertices(vertices, simplices, order)
if fix_orientation:
from meshmode.mesh.processing import (
find_volume_mesh_element_group_orientation,
flip_simplex_element_group)
orient = find_volume_mesh_element_group_orientation(vertices, grp)
grp = flip_simplex_element_group(vertices, grp, orient < 0)
return Mesh(vertices=vertices,
groups=[grp],
nodal_adjacency=None,
facial_adjacency_groups=None)
def from_vertices_and_simplices(vertices, simplices, order=1, fix_orientation=False):
"""Imports a mesh from a numpy array of vertices and an array
of simplices.
:arg vertices:
An array of vertex coordinates with shape
*(ambient_dim, nvertices)*
:arg simplices:
An array *(nelements, nvertices)* of (mesh-wide)
vertex indices.
"""
from meshmode.mesh import Mesh
from meshmode.mesh.generation import make_group_from_vertices
grp = make_group_from_vertices(vertices, simplices, order)
if fix_orientation:
from meshmode.mesh.processing import (
find_volume_mesh_element_group_orientation,
flip_simplex_element_group)
orient = find_volume_mesh_element_group_orientation(vertices, grp)
grp = flip_simplex_element_group(vertices, grp, orient < 0)
return Mesh(
vertices=vertices, groups=[grp],
nodal_adjacency=None,
facial_adjacency_groups=None)
def from_meshpy(mesh_info, order=1):
"""Imports a mesh from a :mod:`meshpy` *mesh_info* data structure,
which may be generated by either :mod:`meshpy.triangle` or
:mod:`meshpy_tet`.
"""
from meshmode.mesh import Mesh
from meshmode.mesh.generation import make_group_from_vertices
vertices = np.array(mesh_info.points).T
elements = np.array(mesh_info.elements, np.int32)
grp = make_group_from_vertices(vertices, elements, order)
# FIXME: Should transfer boundary/volume markers
return Mesh(vertices=vertices, groups=[grp], is_conforming=True)
def from_meshpy(mesh_info, order=1):
"""Imports a mesh from a :mod:`meshpy` *mesh_info* data structure,
which may be generated by either :mod:`meshpy.triangle` or
:mod:`meshpy_tet`.
"""
from meshmode.mesh import Mesh
from meshmode.mesh.generation import make_group_from_vertices
vertices = np.array(mesh_info.points).T
elements = np.array(mesh_info.elements, np.int32)
grp = make_group_from_vertices(vertices, elements, order)
# FIXME: Should transfer boundary/volume markers
return Mesh(
vertices=vertices, groups=[grp],
is_conforming=True)
def test_quad_single_element(visualize=False):
vertices = np.array([
[0.91, 1.10],
[2.64, 1.27],
[0.97, 2.56],
[3.00, 3.41],
]).T
mg = mgen.make_group_from_vertices(vertices,
np.array([[0, 1, 2, 3]],
dtype=np.int32),
30,
group_cls=TensorProductElementGroup)
Mesh(vertices, [mg], nodal_adjacency=None, facial_adjacency_groups=None)
if visualize:
import matplotlib.pyplot as plt
plt.plot(mg.nodes[0].reshape(-1), mg.nodes[1].reshape(-1), "o")
plt.show()
def test_quad_mesh_2d(ambient_dim, filename, visualize=False):
from meshmode.mesh.io import generate_gmsh, ScriptWithFilesSource
logger.info("BEGIN GEN")
mesh = generate_gmsh(
ScriptWithFilesSource(
f"""
Merge "{filename}";
Mesh.CharacteristicLengthMax = 0.05;
Recombine Surface "*" = 0.0001;
Mesh 2;
Save "output.msh";
""", [filename]),
order=1,
force_ambient_dim=ambient_dim,
target_unit="MM",
)
logger.info("END GEN")
logger.info("nelements: %d", mesh.nelements)
groups = []
for grp in mesh.groups:
if not isinstance(grp, TensorProductElementGroup):
# NOTE: gmsh isn't guaranteed to recombine all elements, so we
# could still have some simplices sitting around, so skip them
groups.append(grp.copy())
continue
g = mgen.make_group_from_vertices(mesh.vertices,
grp.vertex_indices,
grp.order,
group_cls=TensorProductElementGroup)
assert g.nodes.shape == (mesh.ambient_dim, grp.nelements,
grp.nunit_nodes)
groups.append(g)
mesh_from_vertices = Mesh(mesh.vertices, groups=groups, is_conforming=True)
if visualize:
from meshmode.mesh.visualization import write_vertex_vtk_file
write_vertex_vtk_file(mesh, "quad_mesh_2d_orig.vtu")
write_vertex_vtk_file(mesh_from_vertices, "quad_mesh_2d_groups.vtu")
def test_quad_single_element():
from meshmode.mesh.generation import make_group_from_vertices
from meshmode.mesh import Mesh, TensorProductElementGroup
vertices = np.array([
[0.91, 1.10],
[2.64, 1.27],
[0.97, 2.56],
[3.00, 3.41],
]).T
mg = make_group_from_vertices(vertices,
np.array([[0, 1, 2, 3]], dtype=np.int32),
30,
group_factory=TensorProductElementGroup)
Mesh(vertices, [mg], nodal_adjacency=None, facial_adjacency_groups=None)
if 0:
import matplotlib.pyplot as plt
plt.plot(mg.nodes[0].reshape(-1), mg.nodes[1].reshape(-1), "o")
plt.show()
def test_quad_single_element():
from meshmode.mesh.generation import make_group_from_vertices
from meshmode.mesh import Mesh, TensorProductElementGroup
vertices = np.array([
[0.91, 1.10],
[2.64, 1.27],
[0.97, 2.56],
[3.00, 3.41],
]).T
mg = make_group_from_vertices(
vertices,
np.array([[0, 1, 2, 3]], dtype=np.int32),
30, group_factory=TensorProductElementGroup)
Mesh(vertices, [mg], nodal_adjacency=None, facial_adjacency_groups=None)
if 0:
import matplotlib.pyplot as plt
plt.plot(
mg.nodes[0].reshape(-1),
mg.nodes[1].reshape(-1), "o")
plt.show()
