def mesh_randomizer_2d(mesh, percentage, preserve_boundary=True):
"""
Randomly perturb a given mesh.
Args:
mesh: Input mesh.
percentage: Maximum perturbation in percentage of mesh.hmin().
preserve_boundary: Whether to move the vertices on the boundary.
Returns:
rmesh: The perturbed mesh.
"""
# Generate a deep copy of the mesh
rmesh = Mesh(mesh)
meshsize = rmesh.hmin()
# Randomly perturbed the mesh
radius = np.random.rand(rmesh.num_vertices()) * percentage * meshsize
theta = np.random.rand(rmesh.num_vertices()) * 2.0 * np.pi
deltax = np.zeros([rmesh.num_vertices(), 2])
deltax[:, 0] = (radius * np.sin(theta)).transpose()
deltax[:, 1] = (radius * np.cos(theta)).transpose()
# What to do with the boundary vertices
if preserve_boundary:
# Exterior means global boundary
boundary_mesh = BoundaryMesh(rmesh, "exterior")
# entity_map contains the indices of vertices on the boundary
boundary_vertices = boundary_mesh.entity_map(0).array()
deltax[boundary_vertices] = 0.0
rmesh.coordinates()[:] = rmesh.coordinates() + deltax
return rmesh
def __init__(self, alpha_params: GeneralizedAlphaParameters,
time_params: TimeSteppingParameters, fem_solver: FemSolver,
boundary_excitation: ExternalExcitation,
field_updates: FieldUpdates, fields: DDDbFields,
mesh: fenics.Mesh, spaces: Spaces, dddb_file_name: str,
initial_material_parameters: np.ndarray,
in_checkpoint_file_name: str, out_checkpoint_file_name: str):
super().__init__(alpha_params, time_params, fem_solver,
boundary_excitation, field_updates, fields)
self.in_checkpoint_file = XDMFCheckpointHandler(
file_name=in_checkpoint_file_name,
append_to_existing=False,
field=fields.imported_displacement_field,
field_name=fields.u_new.name())
self.out_checkpoint_file = XDMFCheckpointHandler(
file_name=out_checkpoint_file_name,
append_to_existing=False,
field=fields.u_new,
field_name=fields.u_new.name())
self.v_out_checkpoint_file = XDMFCheckpointHandler(
file_name='v_{}'.format(out_checkpoint_file_name),
append_to_existing=False,
field=fields.v_old,
field_name=fields.v_old.name())
self.a_out_checkpoint_file = XDMFCheckpointHandler(
file_name='a_{}'.format(out_checkpoint_file_name),
append_to_existing=False,
field=fields.a_old,
field_name=fields.a_old.name())
self.np_files = NPYFile(file_name=dddb_file_name)
self.tensor_space = spaces.tensor_space
self.number_of_vertices = mesh.num_vertices()
self.fields = fields
initial_values_for_optimizer = np.random.random(
self.fields.new_constitutive_relation_multiplicative_parameters.
function_space().dim() - self.fields.function_space.dim())
self.optimizer = ScipyOptimizer(
fields=self.fields,
initial_values=initial_values_for_optimizer,
fem_solver=fem_solver,
spaces=spaces)
def gaussian_mesh_randomizer(mesh, percentage, preserve_boundary=True):
"""
Randomly perturb a given mesh.
Args:
mesh: Input mesh.
percentage: Maximum perturbation in percentage of mesh.hmin().
preserve_boundary: Whether to move the vertices on the boundary.
Returns:
rmesh: The perturbed mesh.
"""
rmesh = Mesh(mesh)
deltax = (np.random.randn(rmesh.num_vertices(),
rmesh.geometry().dim()) * percentage *
rmesh.hmin())
if preserve_boundary:
boundary_mesh = BoundaryMesh(rmesh, "exterior")
boundary_vertices = boundary_mesh.entity_map(0).array()
deltax[boundary_vertices] = 0.0
rmesh.coordinates()[:] = rmesh.coordinates() + deltax
return rmesh
