cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace > Class Template Reference

Detailed description

template<typename ArrayType, typename IndexType, typename MemorySpace>
class cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >

View of a permutation_matrix.

Template Parameters

Array	Type of permutation array view
IndexType	Type used for matrix indices (e.g. int).
MemorySpace	A memory space (e.g. cusp::host_memory or cusp::device_memory)

Overview

A permutation_matrix_view is a view of a permutation_matrix constructed from existing data or iterators.

Example

The following code snippet demonstrates how to create a 3-by-3 permutation_matrix on the host with 3 nonzeros and permutes a coo_matrix by first by row and then by column.

// include the permutation_matrix header file
#include <cusp/coo_matrix.h>
#include <cusp/multiply.h>
#include <cusp/permutation_matrix.h>
#include <cusp/print.h>

int main()
{
  typedef cusp::array1d<int, cusp::host_memory> ArrayType;

  // allocate storage for (3,3) matrix with 5 nonzeros
  cusp::coo_matrix<int,float,cusp::host_memory> A(3,3,5);

  // initialize matrix entries on host
  A.row_indices[0] = 0; A.column_indices[0] = 0; A.values[0] = 10;
  A.row_indices[1] = 0; A.column_indices[1] = 2; A.values[1] = 20;
  A.row_indices[2] = 0; A.column_indices[2] = 0; A.values[2] = 30;
  A.row_indices[3] = 1; A.column_indices[3] = 1; A.values[3] = 40;
  A.row_indices[4] = 2; A.column_indices[4] = 2; A.values[4] = 50;

  // A now represents the following matrix
  //    [10  0 20]
  //    [30 40  0]
  //    [ 0  0 50]

  // generate a index permutation that swaps row or column 0 and 2
  ArrayType permutation(3);
  permutation[0] = 2; // 0 maps to 2
  permutation[1] = 1; // 1 maps to 1
  permutation[2] = 0; // 2 maps to 0

  // allocate storage for (3,3) matrix with 3 nonzeros
  cusp::permutation_matrix_view<ArrayType> P(3, permutation);

  // P now represents the following permutation matrix
  //    [0 0 1]
  //    [0 1 0]
  //    [1 0 0]

  // permute the rows of A
  cusp::coo_matrix<int,float,cusp::host_memory> PA;
  cusp::multiply(P, A, PA);

  // permute the column of PA
  cusp::coo_matrix<int,float,cusp::host_memory> PAP;
  cusp::multiply(PA, P, PAP);

  // print the permuted matrix
  cusp::print(PAP);
}

Definition at line 34 of file permutation_matrix.h.

#include <permutation_matrix.h>

Inheritance diagram for cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >:

Public Methods
	permutation_matrix_view (void)
	permutation_matrix_view (const size_t num_rows, ArrayType &permutation)
	permutation_matrix_view (const size_t num_rows, const ArrayType &permutation)
	permutation_matrix_view (permutation_matrix< IndexType, MemorySpace > &matrix)
	permutation_matrix_view (const permutation_matrix< IndexType, MemorySpace > &matrix)
	permutation_matrix_view (permutation_matrix_view< ArrayType > &matrix)
	permutation_matrix_view (const permutation_matrix_view< ArrayType > &matrix)
void	resize (const size_t num_rows)
template<typename MatrixType >
void	symmetric_permute (MatrixType &matrix)

Public Members
permutation_array_type	permutation

Constructor & Destructor Documentation

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( void  )

inline

Construct an empty permutation_matrix_view.

Definition at line 297 of file permutation_matrix.h.

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( const size_t  num_rows, ArrayType &  permutation  )

inline

Construct a permutation_matrix_view with a specific number of rows from an existing array denoting the permutation indices.

Parameters

num_rows	Number of rows.
permutation	Array containing the permutation indices.

Definition at line 306 of file permutation_matrix.h.

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( const size_t  num_rows, const ArrayType &  permutation  )

inline

Construct a permutation_matrix_view with a specific number of rows from an existing const array denoting the permutation indices.

Parameters

num_rows	Number of rows.
permutation	Array containing the permutation indices.

Definition at line 316 of file permutation_matrix.h.

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( permutation_matrix< IndexType, MemorySpace > &  matrix )

inline

Construct a permutation_matrix_view from a existing permutation_matrix.

Parameters

matrix

permutation_matrix used to create view.

Definition at line 324 of file permutation_matrix.h.

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( const permutation_matrix< IndexType, MemorySpace > &  matrix )

inline

Construct a permutation_matrix_view from a existing const permutation_matrix.

Parameters

matrix

permutation_matrix used to create view.

Definition at line 332 of file permutation_matrix.h.

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( permutation_matrix_view< ArrayType > &  matrix )

inline

Construct a permutation_matrix_view from a existing permutation_matrix_view.

Parameters

matrix

permutation_matrix_view used to create view.

Definition at line 340 of file permutation_matrix.h.

template<typename ArrayType, typename IndexType, typename MemorySpace>

cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation_matrix_view ( const permutation_matrix_view< ArrayType > &  matrix )

inline

Construct a permutation_matrix_view from a existing const permutation_matrix_view.

Parameters

matrix

permutation_matrix_view used to create view.

Definition at line 348 of file permutation_matrix.h.

Member Function Documentation

template<typename ArrayType, typename IndexType, typename MemorySpace>

void cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::resize

(

const size_t

num_rows

)

Resize matrix dimensions and underlying storage

Parameters

num_rows

Number of rows.

template<typename ArrayType, typename IndexType, typename MemorySpace>

template<typename MatrixType >

void cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::symmetric_permute

(

MatrixType &

matrix

)

Permute rows and columns of matrix elements

Parameters

matrix

Input matrix to apply symmetric permutation.

Member Data Documentation

template<typename ArrayType, typename IndexType, typename MemorySpace>

permutation_array_type cusp::permutation_matrix_view< ArrayType, IndexType, MemorySpace >::permutation

Storage for the permutation indices

Definition at line 293 of file permutation_matrix.h.