def main():
mr = HedgeMeshReceiver()
import sys
from meshpy.gmsh_reader import read_gmsh
read_gmsh(mr, sys.argv[1])
def main():
mr = GmshMeshReceiver()
import sys
from meshpy.gmsh_reader import read_gmsh
read_gmsh(mr, sys.argv[1])
def read_gmsh(filename, force_ambient_dim=None):
"""Read a gmsh mesh file from *filename* and return a
:class:`meshmode.mesh.Mesh`.
:arg force_ambient_dim: if not None, truncate point coordinates to
this many dimensions.
"""
from meshpy.gmsh_reader import read_gmsh
recv = GmshMeshReceiver()
read_gmsh(recv, filename, force_dimension=force_ambient_dim)
return recv.get_mesh()
def read_gmsh(filename, force_ambient_dim=None):
"""Read a gmsh mesh file from *filename* and return a
:class:`meshmode.mesh.Mesh`.
:arg force_ambient_dim: if not None, truncate point coordinates to
this many dimensions.
"""
from meshpy.gmsh_reader import read_gmsh
recv = GmshMeshReceiver()
read_gmsh(recv, filename, force_dimension=force_ambient_dim)
return recv.get_mesh()
def read_gmsh(filename, force_dimension=None, periodicity=None,
allow_internal_boundaries=False,
tag_mapper=lambda tag: tag, boundary_tagger=None):
"""
:param force_dimension: if not None, truncate point coordinates to this many dimensions.
"""
mr = HedgeGmshMeshReceiver(force_dimension, tag_mapper)
from meshpy.gmsh_reader import read_gmsh
read_gmsh(mr, filename, force_dimension=force_dimension)
return mr.build_mesh(periodicity=periodicity,
allow_internal_boundaries=allow_internal_boundaries,
tag_mapper=tag_mapper, boundary_tagger=boundary_tagger)
def read_gmsh(fname):
# create a receiver from the GmshMeshReceiverBase interface
rc = reader.GmshMeshReceiverNumPy()
# read the mesh from fname file
rd = reader.read_gmsh(rc, fname)
# points
p = np.array(list(map(lambda x: x[0:2], rc.points)))
# 3 indicies of verticies
t = np.array(list(filter(lambda x: x.shape == (3,), rc.elements)))
# 2 boundary edge indicies
be = np.array(list(filter(lambda x: x.shape == (2,), rc.elements)))
# Dirichlet boundary edge indicies
# find indicies for atributes
I0 = np.nonzero(np.array(list(rc.element_markers)) == 20);
bd0 = np.array(list(rc.elements))[I0[0]]
bd = np.zeros((len(bd0),2));
for j in range(len(bd)):
bd[j][0] = bd0[j][0];
bd[j][1] = bd0[j][1];
#print list(rc.elements)
return (p, t, be, bd)
def read_gmsh(filename,
force_dimension=None,
periodicity=None,
allow_internal_boundaries=False,
tag_mapper=lambda tag: tag,
boundary_tagger=None):
"""
:param force_dimension: if not None, truncate point coordinates to this many dimensions.
"""
mr = HedgeGmshMeshReceiver(force_dimension, tag_mapper)
from meshpy.gmsh_reader import read_gmsh
read_gmsh(mr, filename, force_dimension=force_dimension)
return mr.build_mesh(periodicity=periodicity,
allow_internal_boundaries=allow_internal_boundaries,
tag_mapper=tag_mapper,
boundary_tagger=boundary_tagger)
def build(self, file_name):
### Parse gmsh file
###################
mr = GmshMeshReceiverNumPy()
read_gmsh(mr, file_name)
elem_type_inds = {}
# Find the element types
for i in range(len(mr.element_types)):
e = mr.element_types[i]
if e in elem_type_inds:
elem_type_inds[e] += [i]
else:
elem_type_inds[e] = [i]
# Split out the ones we care about
hex_type = None
quad_type = None
for t in elem_type_inds.keys():
if isinstance(t, GmshHexahedralElement):
hex_type = t
if isinstance(t, GmshQuadrilateralElement):
quad_type = t
if hex_type is None:
raise InvalidGmshMesh("No hex elements found.")
if quad_type is None:
raise InvalidGmshMesh("No quad face elements found.")
assert hex_type.order == 1, "Only linear maps currently supported"
hex_inds = elem_type_inds[hex_type]
hex_inds = np.sort(hex_inds)
quad_inds = elem_type_inds[quad_type]
quad_inds = np.sort(quad_inds)
# Build connectivity maps
elem_to_node = np.zeros((len(hex_inds), hex_type.node_count()),
dtype=np.int)
for i in range(len(hex_inds)):
ind = hex_inds[i]
elem_to_node[i, :] = mr.elements[ind]
bndy_face_to_node = np.zeros((len(quad_inds), quad_type.node_count()),
dtype=np.int)
bf2n = bndy_face_to_node
for i in range(len(quad_inds)):
ind = quad_inds[i]
bf2n[i, :] = mr.elements[ind]
### Nodes array
nodes = np.array(mr.points)
## Remove nodes not linked to elements.
# These show up when nodes used to construct the mesh are not
# nodes of the generated elements.
used_nodes = np.unique(elem_to_node)
max_node = np.max(nodes)
unused_nodes = set(np.arange(max_node)) - set(used_nodes)
unused_nodes = np.sort(list(unused_nodes))
for inode in unused_nodes[::-1]:
elem_to_node[elem_to_node > inode] -= 1
bf2n[bf2n > inode] -= 1
nodes = nodes[used_nodes]
self.nodes = nodes
assert np.all(np.unique(elem_to_node) == np.arange(len(nodes)))
vertices = nodes
self.vertices = vertices
# Switch nodes to lex ordering
inds = hex_type.get_lexicographic_gmsh_node_indices()
elem_to_node = elem_to_node[:, inds]
self.elem_to_node = elem_to_node
inds = quad_type.get_lexicographic_gmsh_node_indices()
bndy_face_to_node = bf2n[:, inds]
self.bndy_face_to_node = bndy_face_to_node
elem_to_vertex = elem_to_node
self.elem_to_vertex = elem_to_vertex
boundary_vertices = np.unique(bndy_face_to_node.ravel())
self.boundary_vertices = boundary_vertices
### Build connectivity arrays
#############################
geom = HexElement
self.geom = geom
# Build set of edges and edge maps
elem_to_edge = np.zeros((len(elem_to_vertex), geom.n_edges),
dtype=np.int)
elem_to_edge_dir = np.zeros((len(elem_to_vertex), geom.n_edges),
dtype=np.int)
edge_id = {}
eid = 0
for ielem in range(len(elem_to_vertex)):
etv = elem_to_vertex[ielem]
elem_edges = etv[geom.edge_to_vertex]
for iedge in range(geom.n_edges):
edge = elem_edges[iedge]
# Edge direction
elem_to_edge_dir[ielem, iedge] = 1 if edge[0] < edge[1] else -1
edge.sort()
t = tuple(edge)
if not t in edge_id:
edge_id[t] = eid
eid += 1
elem_to_edge[ielem, iedge] = edge_id[t]
assert len(edge_id) == eid
edge_to_vertex = np.zeros((len(edge_id), geom.n_vertex_per_edge),
dtype=np.int)
for k, v in edge_id.iteritems():
edge_to_vertex[v, :] = k
assert np.all(edge_to_vertex[:, 0] < edge_to_vertex[:, 1])
self.elem_to_edge = elem_to_edge
self.elem_to_edge_dir = elem_to_edge_dir
self.edge_to_vertex = edge_to_vertex
self.edge_id = edge_id
# Build set of faces and face maps
elem_to_face = np.zeros((len(elem_to_vertex), geom.n_faces),
dtype=np.int)
elem_to_face_dir = np.zeros((len(elem_to_vertex), geom.n_faces),
dtype=np.int)
face_id = {}
fid = 0
for ielem in range(len(elem_to_vertex)):
etv = elem_to_vertex[ielem]
elem_faces = etv[geom.face_to_vertex]
for iface in range(geom.n_faces):
face = elem_faces[iface]
# How far to rotate the face
elem_to_face_dir[ielem, iface] = np.argmin(face)
face.sort()
t = tuple(face)
if not t in face_id:
face_id[t] = fid
fid += 1
elem_to_face[ielem, iface] = face_id[t]
assert len(face_id) == fid
face_to_vertex = np.zeros((len(face_id), geom.n_vertex_per_face),
dtype=np.int)
for k, v in face_id.iteritems():
face_to_vertex[v, :] = k
assert np.all(face_to_vertex[:, 0] < face_to_vertex[:, 1])
assert np.all(face_to_vertex[:, 1] < face_to_vertex[:, 2])
assert np.all(face_to_vertex[:, 2] < face_to_vertex[:, 3])
self.elem_to_face = elem_to_face
self.elem_to_face_dir = elem_to_face_dir
self.face_to_vertex = face_to_vertex
self.face_id = face_id
# Add component counts
self.n_elems = len(elem_to_vertex)
self.n_vertices = len(vertices)
self.n_edges = len(edge_id)
self.n_faces = len(face_id)
# Find edges on the boundary
boundary_edges = []
for iedge in range(self.n_edges):
edge = self.edge_to_vertex[iedge]
if (edge[0] in boundary_vertices) and\
(edge[1] in boundary_vertices):
boundary_edges.append(iedge)
boundary_edges = np.array(boundary_edges, dtype=np.int)
self.boundary_edges = boundary_edges
# Find faces on the boundary
boundary_faces = []
for iface in range(self.n_faces):
face = self.face_to_vertex[iface]
if (face[0] in boundary_vertices) and\
(face[1] in boundary_vertices) and\
(face[2] in boundary_vertices) and\
(face[3] in boundary_vertices):
boundary_faces.append(iface)
boundary_faces = np.array(boundary_faces, dtype=np.int)
self.boundary_faces = boundary_faces
