Dune::ImplicitMatrixBuilder< M_ > Class Template Reference

A wrapper for uniform access to the BCRSMatrix during and after the build stage in implicit build mode. More...

#include <dune/istl/bcrsmatrix.hh>

Classes
class	row_object
	Proxy row object for entry access. More...

Public Types
typedef M_	Matrix
	The underlying matrix.
typedef Matrix::block_type	block_type
	The block_type of the underlying matrix.
typedef Matrix::size_type	size_type
	The size_type of the underlying matrix.

Public Member Functions
	ImplicitMatrixBuilder (Matrix &m)
	Creates an ImplicitMatrixBuilder for matrix m. More...
	ImplicitMatrixBuilder (Matrix &m, size_type rows, size_type cols, size_type avg_cols_per_row, double overflow_fraction)
	Sets up matrix m for implicit construction using the given parameters and creates an ImplicitBmatrixuilder for it. More...
row_object	operator[] (size_type i) const
	Returns a proxy for entries in row i.
size_type	N () const
	The number of rows in the matrix.
size_type	M () const
	The number of columns in the matrix.

Detailed Description

template<class M_>
class Dune::ImplicitMatrixBuilder< M_ >

A wrapper for uniform access to the BCRSMatrix during and after the build stage in implicit build mode.

The implicit build mode of Dune::BCRSMatrix handles matrices differently during assembly and afterwards. Using this class, one can wrap a BCRSMatrix to allow use with code that is not written for the new build mode specifically. The wrapper forwards any calls to operator[][] to the entry() method.The assembly code does not even necessarily need to know that the underlying matrix is sparse. Dune::AMG uses this to reassemble an existing matrix without code duplication. The compress() method of Dune::BCRSMatrix still has to be called from outside this wrapper after the pattern assembly is finished.

Template Parameters

M_	the matrix type

Constructor & Destructor Documentation

ImplicitMatrixBuilder() [1/2]

template<class M_ >

Dune::ImplicitMatrixBuilder< M_ >::ImplicitMatrixBuilder ( Matrix &  m )

inline

Creates an ImplicitMatrixBuilder for matrix m.

Note

You can only pass a completely set up matrix to this constructor: All of setBuildMode(), setImplicitBuildModeParameters() and setSize() must have been called with the correct values.

References DUNE_THROW.

ImplicitMatrixBuilder() [2/2]

template<class M_ >

Dune::ImplicitMatrixBuilder< M_ >::ImplicitMatrixBuilder ( Matrix &  m, size_type  rows, size_type  cols, size_type  avg_cols_per_row, double  overflow_fraction  )

inline

Sets up matrix m for implicit construction using the given parameters and creates an ImplicitBmatrixuilder for it.

Using this constructor, you can perform the necessary matrix setup and the creation of the ImplicitMatrixBuilder in a single step. The matrix must still be in the build stage notAllocated, otherwise a BCRSMatrixError will be thrown. For a detailed explanation of the matrix parameters, see BCRSMatrix.

Parameters

m	the matrix to be built
rows	the number of matrix rows
cols	the number of matrix columns
avg_cols_per_row	the average number of non-zero columns per row
overflow_fraction	the amount of overflow to reserve in the matrix

See also

BCRSMatrix

References DUNE_THROW.

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

• dune/istl/bcrsmatrix.hh