cusp::ell_matrix< IndexType, ValueType, MemorySpace > Class Template Reference

Detailed description

template<typename IndexType, typename ValueType, typename MemorySpace>
class cusp::ell_matrix< IndexType, ValueType, MemorySpace >

Packed row (ELLPACK/ITPACK) representation of a sparse matrix.

Template Parameters

IndexType	Type used for matrix indices (e.g. int).
ValueType	Type used for matrix values (e.g. float).
MemorySpace	A memory space (e.g. cusp::host_memory or cusp::device_memory)

Overview

Note

The matrix entries must be sorted by column index.

The matrix entries within each row should be shifted to the left.

The matrix should not contain duplicate entries.

Example

The following code snippet demonstrates how to create a 4-by-3 ell_matrix on the host with 3 nonzeros per row (6 total nonzeros) and then copies the matrix to the device.

// include the ell_matrix header file
#include <cusp/ell_matrix.h>
#include <cusp/print.h>

int main()
{
  // allocate storage for (4,3) matrix with 6 nonzeros and at most 3 nonzeros per row.
  cusp::ell_matrix<int,float,cusp::host_memory> A(4,3,6,3);

  // X is used to fill unused entries in the matrix
  const int X = cusp::ell_matrix<int,float,cusp::host_memory>::invalid_index;

  // initialize matrix entries on host
  A.column_indices(0,0) = 0; A.values(0,0) = 10;
  A.column_indices(0,1) = 2; A.values(0,1) = 20;  // shifted to leftmost position
  A.column_indices(0,2) = X; A.values(0,2) =  0;  // padding

  A.column_indices(1,0) = X; A.values(1,0) =  0;  // padding
  A.column_indices(1,1) = X; A.values(1,1) =  0;  // padding
  A.column_indices(1,2) = X; A.values(1,2) =  0;  // padding

  A.column_indices(2,0) = 2; A.values(2,0) = 30;  // shifted to leftmost position
  A.column_indices(2,1) = X; A.values(2,1) =  0;  // padding
  A.column_indices(2,2) = X; A.values(2,2) =  0;  // padding

  A.column_indices(3,0) = 0; A.values(3,0) = 40;
  A.column_indices(3,1) = 1; A.values(3,1) = 50;
  A.column_indices(3,2) = 2; A.values(3,2) = 60;

  // A now represents the following matrix
  //    [10  0 20]
  //    [ 0  0  0]
  //    [ 0  0 30]
  //    [40 50 60]

  // copy to the device
  cusp::ell_matrix<int,float,cusp::device_memory> B(A);

  cusp::print(B);
}

Examples:

ell.cu, and hyb.cu.

Definition at line 122 of file ell_matrix.h.

#include <ell_matrix.h>

Inheritance diagram for cusp::ell_matrix< IndexType, ValueType, MemorySpace >:

Public Methods
	ell_matrix (void)
	ell_matrix (const size_t num_rows, const size_t num_cols, const size_t num_entries, const size_t num_entries_per_row, const size_t alignment=32)
template<typename MatrixType >
	ell_matrix (const MatrixType &matrix)
void	resize (const size_t num_rows, const size_t num_cols, const size_t num_entries, const size_t num_entries_per_row)
void	resize (const size_t num_rows, const size_t num_cols, const size_t num_entries, const size_t num_entries_per_row, const size_t alignment)
void	swap (ell_matrix &matrix)
template<typename MatrixType >
ell_matrix &	operator= (const MatrixType &matrix)

Public Members
column_indices_array_type	column_indices
values_array_type	values

Static Public Members
static const IndexType	invalid_index = static_cast<IndexType>(-1)

Constructor & Destructor Documentation

template<typename IndexType, typename ValueType, typename MemorySpace>

cusp::ell_matrix< IndexType, ValueType, MemorySpace >::ell_matrix ( void  )

inline

Construct an empty ell_matrix.

Definition at line 170 of file ell_matrix.h.

template<typename IndexType, typename ValueType, typename MemorySpace>

cusp::ell_matrix< IndexType, ValueType, MemorySpace >::ell_matrix	(	const size_t	num_rows,
		const size_t	num_cols,
		const size_t	num_entries,
		const size_t	num_entries_per_row,
		const size_t	alignment = 32
	)

Construct an ell_matrix with a specific shape, number of nonzero entries, and maximum number of nonzero entries per row.

Parameters

num_rows	Number of rows.
num_cols	Number of columns.
num_entries	Number of nonzero matrix entries.
num_entries_per_row	Maximum number of nonzeros per row.
alignment	Amount of padding used to align the data structure (default 32).

template<typename IndexType, typename ValueType, typename MemorySpace>

template<typename MatrixType >

cusp::ell_matrix< IndexType, ValueType, MemorySpace >::ell_matrix

(

const MatrixType &

matrix

)

Construct an ell_matrix from another matrix.

Parameters

matrix

Another sparse or dense matrix.

Member Function Documentation

template<typename IndexType, typename ValueType, typename MemorySpace>

template<typename MatrixType >

ell_matrix& cusp::ell_matrix< IndexType, ValueType, MemorySpace >::operator=

(

const MatrixType &

matrix

)

Assignment from another matrix.

Template Parameters

MatrixType

Format type of input matrix.

Parameters

matrix

Another sparse or dense matrix.

template<typename IndexType, typename ValueType, typename MemorySpace>

void cusp::ell_matrix< IndexType, ValueType, MemorySpace >::resize	(	const size_t	num_rows,
		const size_t	num_cols,
		const size_t	num_entries,
		const size_t	num_entries_per_row
	)

Resize matrix dimensions and underlying storage

Parameters

num_rows	Number of rows.
num_cols	Number of columns.
num_entries	Number of nonzero matrix entries.
num_entries_per_row	Maximum number of nonzeros per row.

template<typename IndexType, typename ValueType, typename MemorySpace>

void cusp::ell_matrix< IndexType, ValueType, MemorySpace >::resize	(	const size_t	num_rows,
		const size_t	num_cols,
		const size_t	num_entries,
		const size_t	num_entries_per_row,
		const size_t	alignment
	)

Resize matrix dimensions and underlying storage

Parameters

num_rows	Number of rows.
num_cols	Number of columns.
num_entries	Number of nonzero matrix entries.
num_entries_per_row	Maximum number of nonzeros per row.
alignment	Amount of padding used to align the data structure (default 32).

template<typename IndexType, typename ValueType, typename MemorySpace>

void cusp::ell_matrix< IndexType, ValueType, MemorySpace >::swap

(

ell_matrix< IndexType, ValueType, MemorySpace > &

matrix

)

Swap the contents of two ell_matrix objects.

Parameters

matrix

Another ell_matrix with the same IndexType and ValueType.

Member Data Documentation

template<typename IndexType, typename ValueType, typename MemorySpace>

column_indices_array_type cusp::ell_matrix< IndexType, ValueType, MemorySpace >::column_indices

Storage for the column indices of the ELL data structure.

Definition at line 162 of file ell_matrix.h.

template<typename IndexType, typename ValueType, typename MemorySpace>

const IndexType cusp::ell_matrix< IndexType, ValueType, MemorySpace >::invalid_index = static_cast<IndexType>(-1)

static

Value used to pad the rows of the column_indices array.

Definition at line 132 of file ell_matrix.h.

template<typename IndexType, typename ValueType, typename MemorySpace>

values_array_type cusp::ell_matrix< IndexType, ValueType, MemorySpace >::values

Storage for the nonzero entries of the ELL data structure.

Definition at line 166 of file ell_matrix.h.