TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index > Class Template Reference

RowView is a simple structure for accessing rows of Lambda matrix. More...

#include <TNL/Matrices/LambdaMatrixRowView.h>

Public Types
using	CompressedRowLengthsLambdaType = CompressedRowLengthsLambda
	Type of the lambda function returning the number of non-zero elements in each row.
using	ConstRowView = RowView
	Type of constant Lambda matrix row view.
using	IndexType = Index
	The type used for matrix elements indexing.
using	IteratorType = LambdaMatrixRowViewIterator< RowView >
	Type of iterator for the matrix row.
using	MatrixElementsLambdaType = MatrixElementsLambda
	Type of the lambda function returning the matrix elements.
using	MatrixElementType = LambdaMatrixElement< RealType, IndexType >
	The type of related matrix element.
using	RealType = Real
	The type of matrix elements.
using	RowView = LambdaMatrixRowView< MatrixElementsLambdaType, CompressedRowLengthsLambdaType, RealType, IndexType >
	Type of Lambda matrix row view.

Public Member Functions
__cuda_callable__	LambdaMatrixRowView (const MatrixElementsLambdaType &matrixElementsLambda, const CompressedRowLengthsLambdaType &compressedRowLengthsLambda, const IndexType &rows, const IndexType &columns, const IndexType &rowIdx)
	Constructor with related lambda functions, matrix dimensions and row index.
__cuda_callable__ IteratorType	begin () const
	Returns non-constant iterator pointing at the beginning of the matrix row.
__cuda_callable__ IteratorType	cbegin () const
	Returns constant iterator pointing at the beginning of the matrix row.
__cuda_callable__ IteratorType	cend () const
	Returns constant iterator pointing at the end of the matrix row.
__cuda_callable__ IteratorType	end () const
	Returns non-constant iterator pointing at the end of the matrix row.
__cuda_callable__ IndexType	getColumnIndex (IndexType localIdx) const
	Returns constants reference to a column index of an element with given rank in the row.
__cuda_callable__ const IndexType &	getRowIndex () const
	Returns the matrix row index.
__cuda_callable__ IndexType	getSize () const
	Returns size of the matrix row, i.e. number of matrix elements in this row.
__cuda_callable__ RealType	getValue (IndexType localIdx) const
	Returns constants reference to value of an element with given rank in the row.
template<typename MatrixElementsLambda_ , typename CompressedRowLengthsLambda_ , typename Real_ , typename Index_ >
__cuda_callable__ bool	operator== (const LambdaMatrixRowView< MatrixElementsLambda_, CompressedRowLengthsLambda_, Real_, Index_ > &other) const
	Comparison of two matrix rows.

Protected Attributes
IndexType	columns
const CompressedRowLengthsLambda &	compressedRowLengthsLambda
const MatrixElementsLambda &	matrixElementsLambda
IndexType	rowIdx
IndexType	rows

Detailed Description

template<typename MatrixElementsLambda, typename CompressedRowLengthsLambda, typename Real = double, typename Index = int>
class TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >

RowView is a simple structure for accessing rows of Lambda matrix.

Template Parameters

MatrixElementsLambda

is a lambda function returning matrix elements values and positions.

It has the following form:

auto matrixElements = [] __cuda_callable__ ( Index rows, Index columns, Index rowIdx, Index localIdx, Index& columnIdx, Real&
value ) { ... }

where rows is the number of matrix rows, columns is the number of matrix columns, rowIdx is the index of matrix row being queried, localIdx is the rank of the non-zero element in given row, columnIdx is a column index of the matrix element computed by this lambda and value is a value of the matrix element computed by this lambda.

Template Parameters

CompressedRowLengthsLambda

is a lambda function returning a number of non-zero elements in each row.

It has the following form:

auto rowLengths = [] __cuda_callable__ ( Index rows, Index columns, Index rowIdx ) -> IndexType { ... }

where rows is the number of matrix rows, columns is the number of matrix columns and rowIdx is an index of the row being queried.

Template Parameters

Real	is a type of matrix elements values.
Index	is a type to be used for indexing.

Example

#include <iostream>
#include <TNL/Algorithms/parallelFor.h>
#include <TNL/Matrices/LambdaMatrix.h>
#include <TNL/Matrices/DenseMatrix.h>
#include <TNL/Devices/Host.h>
#include <TNL/Devices/Cuda.h>
 
template< typename Device >
void
getRowExample()
{
   /***
    * Set  matrix representing approximation of the Laplace operator on regular
    * grid using the finite difference method.
    */
   const int gridSize( 4 );
   const int matrixSize = gridSize * gridSize;
   auto rowLengths = [ = ] __cuda_callable__( const int rows, const int columns, const int rowIdx ) -> int
   {
      const int gridRow = rowIdx / gridSize;  // coordinates in the numerical grid
      const int gridColumn = rowIdx % gridSize;
      if( gridRow == 0 || gridRow == gridSize - 1 ||  // boundary grid node
          gridColumn == 0 || gridColumn == gridSize - 1 )
         return 1;
      return 5;
   };
   auto matrixElements =
      [ = ] __cuda_callable__(
         const int rows, const int columns, const int rowIdx, const int localIdx, int& columnIdx, double& value )
   {
      const int gridRow = rowIdx / gridSize;  // coordinates in the numerical grid
      const int gridColumn = rowIdx % gridSize;
      if( gridRow == 0 || gridRow == gridSize - 1 ||  // boundary grid node
          gridColumn == 0 || gridColumn == gridSize - 1 )
      {
         columnIdx = rowIdx;  // diagonal element ....
         value = 1.0;         // ... is set to 1
      }
      else  // interior grid node
      {
         switch( localIdx )  // set diagonal element to 4
         {                   // and the others to -1
            case 0:
               columnIdx = rowIdx - gridSize;
               value = 1;
               break;
            case 1:
               columnIdx = rowIdx - 1;
               value = 1;
               break;
            case 2:
               columnIdx = rowIdx;
               value = -4;
               break;
            case 3:
               columnIdx = rowIdx + 1;
               value = 1;
               break;
            case 4:
               columnIdx = rowIdx + gridSize;
               value = 1;
               break;
         }
      }
   };
   auto matrix =
      TNL::Matrices::LambdaMatrixFactory< double, Device, int >::create( matrixSize, matrixSize, matrixElements, rowLengths );
 
   TNL::Matrices::DenseMatrix< double, Device > denseMatrix( matrixSize, matrixSize );
   denseMatrix.setValue( 0.0 );
   auto dense_view = denseMatrix.getView();
   auto f = [ = ] __cuda_callable__( const int& rowIdx ) mutable
   {
      auto row = matrix.getRow( rowIdx );
      auto dense_row = dense_view.getRow( rowIdx );
      for( int localIdx = 0; localIdx < row.getSize(); localIdx++ )
         dense_row.setValue( row.getColumnIndex( localIdx ), row.getValue( localIdx ) );
   };
   TNL::Algorithms::parallelFor< Device >( 0, matrixSize, f );
 
   std::cout << "Laplace operator lambda matrix: " << std::endl << matrix << std::endl;
   std::cout << "Laplace operator dense matrix: " << std::endl << denseMatrix << std::endl;
}
 
int
main( int argc, char* argv[] )
{
   std::cout << "Running example on CPU ... " << std::endl;
   getRowExample< TNL::Devices::Host >();
 
#ifdef __CUDACC__
   std::cout << "Running example on CUDA GPU ... " << std::endl;
   getRowExample< TNL::Devices::Cuda >();
#endif
}

Output

Running example on CPU ... 
Laplace operator lambda matrix: 
Row: 0 ->     0:1   
Row: 1 ->     1:1   
Row: 2 ->     2:1   
Row: 3 ->     3:1   
Row: 4 ->     4:1   
Row: 5 ->     1:1       4:1       5:-4      6:1       9:1   
Row: 6 ->     2:1       5:1       6:-4      7:1      10:1   
Row: 7 ->     7:1   
Row: 8 ->     8:1   
Row: 9 ->     5:1       8:1       9:-4     10:1      13:1   
Row: 10 ->     6:1       9:1      10:-4     11:1      14:1   
Row: 11 ->    11:1   
Row: 12 ->    12:1   
Row: 13 ->    13:1   
Row: 14 ->    14:1   
Row: 15 ->    15:1   
 
Laplace operator dense matrix: 
Row: 0 ->     0:1       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 1 ->     0:0       1:1       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 2 ->     0:0       1:0       2:1       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 3 ->     0:0       1:0       2:0       3:1       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 4 ->     0:0       1:0       2:0       3:0       4:1       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 5 ->     0:0       1:1       2:0       3:0       4:1       5:-4      6:1       7:0       8:0       9:1      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 6 ->     0:0       1:0       2:1       3:0       4:0       5:1       6:-4      7:1       8:0       9:0      10:1      11:0      12:0      13:0      14:0      15:0   
Row: 7 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:1       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 8 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:1       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 9 ->     0:0       1:0       2:0       3:0       4:0       5:1       6:0       7:0       8:1       9:-4     10:1      11:0      12:0      13:1      14:0      15:0   
Row: 10 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:1       7:0       8:0       9:1      10:-4     11:1      12:0      13:0      14:1      15:0   
Row: 11 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:1      12:0      13:0      14:0      15:0   
Row: 12 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:1      13:0      14:0      15:0   
Row: 13 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:1      14:0      15:0   
Row: 14 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:1      15:0   
Row: 15 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:1   
Running example on CUDA GPU ... 
Laplace operator lambda matrix: 
Row: 0 ->     0:1   
Row: 1 ->     1:1   
Row: 2 ->     2:1   
Row: 3 ->     3:1   
Row: 4 ->     4:1   
Row: 5 ->     1:1       4:1       5:-4      6:1       9:1   
Row: 6 ->     2:1       5:1       6:-4      7:1      10:1   
Row: 7 ->     7:1   
Row: 8 ->     8:1   
Row: 9 ->     5:1       8:1       9:-4     10:1      13:1   
Row: 10 ->     6:1       9:1      10:-4     11:1      14:1   
Row: 11 ->    11:1   
Row: 12 ->    12:1   
Row: 13 ->    13:1   
Row: 14 ->    14:1   
Row: 15 ->    15:1   
 
Laplace operator dense matrix: 
Row: 0 ->     0:1       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 1 ->     0:0       1:1       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 2 ->     0:0       1:0       2:1       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 3 ->     0:0       1:0       2:0       3:1       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 4 ->     0:0       1:0       2:0       3:0       4:1       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 5 ->     0:0       1:1       2:0       3:0       4:1       5:-4      6:1       7:0       8:0       9:1      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 6 ->     0:0       1:0       2:1       3:0       4:0       5:1       6:-4      7:1       8:0       9:0      10:1      11:0      12:0      13:0      14:0      15:0   
Row: 7 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:1       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 8 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:1       9:0      10:0      11:0      12:0      13:0      14:0      15:0   
Row: 9 ->     0:0       1:0       2:0       3:0       4:0       5:1       6:0       7:0       8:1       9:-4     10:1      11:0      12:0      13:1      14:0      15:0   
Row: 10 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:1       7:0       8:0       9:1      10:-4     11:1      12:0      13:0      14:1      15:0   
Row: 11 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:1      12:0      13:0      14:0      15:0   
Row: 12 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:1      13:0      14:0      15:0   
Row: 13 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:1      14:0      15:0   
Row: 14 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:1      15:0   
Row: 15 ->     0:0       1:0       2:0       3:0       4:0       5:0       6:0       7:0       8:0       9:0      10:0      11:0      12:0      13:0      14:0      15:1   

Constructor & Destructor Documentation

LambdaMatrixRowView()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::LambdaMatrixRowView	(	const MatrixElementsLambdaType &	matrixElementsLambda,
		const CompressedRowLengthsLambdaType &	compressedRowLengthsLambda,
		const IndexType &	rows,
		const IndexType &	columns,
		const IndexType &	rowIdx )

Constructor with related lambda functions, matrix dimensions and row index.

Parameters

matrixElementsLambda	is a constant reference to the lambda function evaluating matrix elements.
compressedRowLengthsLambda	is a constant reference to the lambda function returning the number of nonzero elements in each row.
rows	is number of matrix rows.
columns	is number of matrix columns.
rowIdx	is the matrix row index.

Member Function Documentation

begin()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::begin

(

)

const

Returns non-constant iterator pointing at the beginning of the matrix row.

Returns

iterator pointing at the beginning.

cbegin()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::cbegin

(

)

const

Returns constant iterator pointing at the beginning of the matrix row.

Returns

iterator pointing at the beginning.

cend()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::cend

(

)

const

Returns constant iterator pointing at the end of the matrix row.

Returns

iterator pointing at the end.

end()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::end

(

)

const

Returns non-constant iterator pointing at the end of the matrix row.

Returns

iterator pointing at the end.

getColumnIndex()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::getColumnIndex

(

IndexType

localIdx

)

const

Returns constants reference to a column index of an element with given rank in the row.

Parameters

localIdx

is the rank of the non-zero element in given row.

Returns

constant reference to the matrix element column index.

getRowIndex()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::getRowIndex

(

)

const

Returns the matrix row index.

Returns

matrix row index.

getSize()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::getSize

(

)

const

Returns size of the matrix row, i.e. number of matrix elements in this row.

Returns

Size of the matrix row.

getValue()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

__cuda_callable__ auto TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::getValue

(

IndexType

localIdx

)

const

Returns constants reference to value of an element with given rank in the row.

Parameters

localIdx

is the rank of the non-zero element in given row.

Returns

constant reference to the matrix element value.

operator==()

template<typename MatrixElementsLambda , typename CompressedRowLengthsLambda , typename Real , typename Index >

template<typename MatrixElementsLambda_ , typename CompressedRowLengthsLambda_ , typename Real_ , typename Index_ >

__cuda_callable__ bool TNL::Matrices::LambdaMatrixRowView< MatrixElementsLambda, CompressedRowLengthsLambda, Real, Index >::operator==

(

const LambdaMatrixRowView< MatrixElementsLambda_, CompressedRowLengthsLambda_, Real_, Index_ > &

other

)

const

Comparison of two matrix rows.

The other matrix row can be from any other matrix.

Parameters

other

is another matrix row.

Returns

true if both rows are the same, false otherwise.

---

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

• src/TNL/Matrices/LambdaMatrixRowView.h
• src/TNL/Matrices/LambdaMatrixRowView.hpp