libMesh::METIS_CSR_Graph< IndexType > Class Template Reference

Compressed graph data structure used by MetisPartitioner. More...

#include <metis_csr_graph.h>

Public Member Functions
void	prep_n_nonzeros (const libMesh::dof_id_type row, const libMesh::dof_id_type n_nonzeros_in)
libMesh::dof_id_type	n_nonzeros (const libMesh::dof_id_type row) const
void	prepare_for_use ()
IndexType &	operator() (const libMesh::dof_id_type row, const libMesh::dof_id_type nonzero)
const IndexType &	operator() (const libMesh::dof_id_type row, const libMesh::dof_id_type nonzero) const

Public Attributes
std::vector< IndexType >	offsets
std::vector< IndexType >	vals

Detailed Description

template<class IndexType>
class libMesh::METIS_CSR_Graph< IndexType >

Compressed graph data structure used by MetisPartitioner.

This utility class provides a convenient implementation for building the compressed-row-storage graph required for the METIS/ParMETIS graph partitioning schemes.

Author

Benjamin S. Kirk

Date

2013

Definition at line 43 of file metis_csr_graph.h.

Member Function Documentation

n_nonzeros()

template<class IndexType>

libMesh::dof_id_type libMesh::METIS_CSR_Graph< IndexType >::n_nonzeros ( const libMesh::dof_id_type  row ) const

inline

Returns

The number of nonzeros in the requested row by subtracting the offsets vector entries.

Definition at line 63 of file metis_csr_graph.h.

References libMesh::METIS_CSR_Graph< IndexType >::offsets.

  {
    libmesh_assert_less (row+1, offsets.size());
    return (offsets[row+1] - offsets[row]);
  }

operator()() [1/2]

template<class IndexType>

IndexType& libMesh::METIS_CSR_Graph< IndexType >::operator() ( const libMesh::dof_id_type  row, const libMesh::dof_id_type  nonzero  )

inline

Returns

A writable reference to the nonzero'th entry of row.

Definition at line 86 of file metis_csr_graph.h.

References libMesh::METIS_CSR_Graph< IndexType >::offsets, and libMesh::METIS_CSR_Graph< IndexType >::vals.

  {
    libmesh_assert_greater (vals.size(), offsets[row]+nonzero);

    return vals[offsets[row]+nonzero];
  }

operator()() [2/2]

template<class IndexType>

const IndexType& libMesh::METIS_CSR_Graph< IndexType >::operator() ( const libMesh::dof_id_type  row, const libMesh::dof_id_type  nonzero  ) const

inline

Returns

A const reference to the nonzero'th entry of row.

Definition at line 97 of file metis_csr_graph.h.

References libMesh::METIS_CSR_Graph< IndexType >::offsets, and libMesh::METIS_CSR_Graph< IndexType >::vals.

  {
    libmesh_assert_greater (vals.size(), offsets[row]+nonzero);

    return vals[offsets[row]+nonzero];
  }

prep_n_nonzeros()

template<class IndexType>

void libMesh::METIS_CSR_Graph< IndexType >::prep_n_nonzeros ( const libMesh::dof_id_type  row, const libMesh::dof_id_type  n_nonzeros_in  )

inline

Sets the number of non-zero values in the given row. The internal indexing is 1-based.

Definition at line 52 of file metis_csr_graph.h.

References libMesh::METIS_CSR_Graph< IndexType >::offsets.

Referenced by libMesh::MetisPartitioner::partition_range().

  {
    libmesh_assert_less (row+1, offsets.size());
    offsets[row+1] = n_nonzeros_in;
  }

prepare_for_use()

template<class IndexType>

void libMesh::METIS_CSR_Graph< IndexType >::prepare_for_use ( )

inline

Replaces the entries in the offsets vector with their partial sums and resizes the val vector accordingly.

Definition at line 73 of file metis_csr_graph.h.

References libMesh::METIS_CSR_Graph< IndexType >::offsets, and libMesh::METIS_CSR_Graph< IndexType >::vals.

Referenced by libMesh::MetisPartitioner::partition_range().

  {
    std::partial_sum (offsets.begin(), offsets.end(), offsets.begin());
    libmesh_assert (!offsets.empty());
    vals.resize(offsets.back());

    if (vals.empty())
      vals.push_back(0);
  }

Member Data Documentation

offsets

template<class IndexType>

std::vector<IndexType> libMesh::METIS_CSR_Graph< IndexType >::offsets

Definition at line 46 of file metis_csr_graph.h.

Referenced by libMesh::METIS_CSR_Graph< IndexType >::n_nonzeros(), libMesh::METIS_CSR_Graph< IndexType >::operator()(), libMesh::MetisPartitioner::partition_range(), libMesh::METIS_CSR_Graph< IndexType >::prep_n_nonzeros(), and libMesh::METIS_CSR_Graph< IndexType >::prepare_for_use().

vals

template<class IndexType>

std::vector<IndexType> libMesh::METIS_CSR_Graph< IndexType >::vals

Definition at line 46 of file metis_csr_graph.h.

Referenced by libMesh::METIS_CSR_Graph< IndexType >::operator()(), libMesh::MetisPartitioner::partition_range(), and libMesh::METIS_CSR_Graph< IndexType >::prepare_for_use().

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

• metis_csr_graph.h