mfem::MeshPartitioner Class Reference

Class that allows serial meshes to be partitioned into MeshPart objects, typically one MeshPart at a time, which can then be used to write the local mesh in parallel MFEM mesh format. More...

#include <mesh.hpp>

Collaboration diagram for mfem::MeshPartitioner:

Public Member Functions
	MeshPartitioner (Mesh &mesh_, int num_parts_, const int *partitioning_=nullptr, int part_method=1)
	Construct a MeshPartitioner.
void	ExtractPart (int part_id, MeshPart &mesh_part) const
	Construct a MeshPart corresponding to the given part_id.
std::unique_ptr< FiniteElementSpace >	ExtractFESpace (MeshPart &mesh_part, const FiniteElementSpace &global_fespace) const
	Construct a local version of the given FiniteElementSpace global_fespace corresponding to the given mesh_part.
std::unique_ptr< GridFunction >	ExtractGridFunction (const MeshPart &mesh_part, const GridFunction &global_gf, FiniteElementSpace &local_fespace) const
	Construct a local version of the given GridFunction, global_gf, corresponding to the given mesh_part. The respective data is copied from global_gf to the returned local GridFunction.

Protected Attributes
Mesh &	mesh
Array< int >	partitioning
Table	part_to_element
Table	part_to_boundary
Table	edge_to_element
Table	vertex_to_element

Detailed Description

Class that allows serial meshes to be partitioned into MeshPart objects, typically one MeshPart at a time, which can then be used to write the local mesh in parallel MFEM mesh format.

Sample usage of this class: partition a serial mesh and save it in parallel MFEM format:

// The array 'partitioning' can be obtained e.g. from
// mesh->GeneratePartitioning():
void usage1(Mesh *mesh, int num_parts, int *partitioning)
{
   MeshPartitioner partitioner(*mesh, num_parts, partitioning);
   MeshPart mesh_part;
   for (int i = 0; i < num_parts; i++)
   {
      partitioner.ExtractPart(i, mesh_part);
      ofstream omesh(MakeParFilename("my-mesh.", i));
      mesh_part.Print(omesh);
   }
}

This class can also be used to partition a mesh and GridFunction(s) and save them in parallel:

// The array 'partitioning' can be obtained e.g. from
// mesh->GeneratePartitioning():
void usage2(Mesh *mesh, int num_parts, int *partitioning,
            GridFunction *gf)
{
   MeshPartitioner partitioner(*mesh, num_parts, partitioning);
   MeshPart mesh_part;
   for (int i = 0; i < num_parts; i++)
   {
      partitioner.ExtractPart(i, mesh_part);
      ofstream omesh(MakeParFilename("my-mesh.", i));
      mesh_part.Print(omesh);
      auto lfes = partitioner.ExtractFESpace(mesh_part, *gf->FESpace());
      auto lgf = partitioner.ExtractGridFunction(mesh_part, *gf, *lfes);
      ofstream ofield(MakeParFilename("my-field.", i));
      lgf->Save(ofield);
   }
}

Definition at line 2853 of file mesh.hpp.

Constructor & Destructor Documentation

MeshPartitioner()

mfem::MeshPartitioner::MeshPartitioner	(	Mesh &	mesh_,
		int	num_parts_,
		const int *	partitioning_ = nullptr,
		int	part_method = 1 )

Construct a MeshPartitioner.

Parameters

[in]	mesh_	Mesh to be partitioned into MeshParts.
[in]	num_parts_	Number of parts to partition the mesh into.
[in]	partitioning_	Partitioning array: for every element in the mesh gives the partition it belongs to; if NULL, partitioning will be generated internally by calling Mesh::GeneratePartitioning().
[in]	part_method	Partitioning method to be used in the call to Mesh::GeneratePartitioning() when the provided input partitioning is NULL.

Definition at line 13926 of file mesh.cpp.

Member Function Documentation

ExtractFESpace()

std::unique_ptr< FiniteElementSpace > mfem::MeshPartitioner::ExtractFESpace	(	MeshPart &	mesh_part,
		const FiniteElementSpace &	global_fespace ) const

Construct a local version of the given FiniteElementSpace global_fespace corresponding to the given mesh_part.

Parameters

[in,out]	mesh_part	MeshPart on which to construct the local FiniteElementSpace; this object is generally modified by this call since it calls mesh_part.GetMesh() to ensure the local mesh is constructed.
[in]	global_fespace	The global FiniteElementSpace that should be restricted to the mesh_part.

Returns

A FiniteElementSpace pointer stored in a unique_ptr. The returned local FiniteElementSpace is built on the Mesh object contained in mesh_part (MeshPart::mesh) and it reuses the FiniteElementCollection of the global_fespace.

Definition at line 14468 of file mesh.cpp.

ExtractGridFunction()

std::unique_ptr< GridFunction > mfem::MeshPartitioner::ExtractGridFunction	(	const MeshPart &	mesh_part,
		const GridFunction &	global_gf,
		FiniteElementSpace &	local_fespace ) const

Construct a local version of the given GridFunction, global_gf, corresponding to the given mesh_part. The respective data is copied from global_gf to the returned local GridFunction.

Parameters

[in]	mesh_part	MeshPart on which to construct the local GridFunction.
[in]	global_gf	The global GridFunction that should be restricted to the mesh_part.
[in,out]	local_fespace	The local FiniteElementSpace corresponding to mesh_part, e.g. constructed by the method ExtractFESpace().

Returns

A GridFunction pointer stored in a unique_ptr. The returned local GridFunction is initialized with data appropriately copied from global_gf.

Definition at line 14483 of file mesh.cpp.

ExtractPart()

void mfem::MeshPartitioner::ExtractPart	(	int	part_id,
		MeshPart &	mesh_part ) const

Construct a MeshPart corresponding to the given part_id.

Parameters

[in]	part_id	Partition index to extract; valid values are in the range [0, num_parts).
[out]	mesh_part	Output MeshPart object; its contents is overwritten, while potentially reusing existing dynamic memory allocations.

Definition at line 13998 of file mesh.cpp.

Member Data Documentation

edge_to_element

Table mfem::MeshPartitioner::edge_to_element

protected

Definition at line 2860 of file mesh.hpp.

mesh

Mesh& mfem::MeshPartitioner::mesh

protected

Definition at line 2856 of file mesh.hpp.

part_to_boundary

Table mfem::MeshPartitioner::part_to_boundary

protected

Definition at line 2859 of file mesh.hpp.

part_to_element

Table mfem::MeshPartitioner::part_to_element

protected

Definition at line 2858 of file mesh.hpp.

partitioning

Array<int> mfem::MeshPartitioner::partitioning

protected

Definition at line 2857 of file mesh.hpp.

vertex_to_element

Table mfem::MeshPartitioner::vertex_to_element

protected

Definition at line 2861 of file mesh.hpp.

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The documentation for this class was generated from the following files:

• mesh/mesh.hpp
• mesh/mesh.cpp