Sparse Matrix and Vector classes
[Iterative Solvers Template Library (ISTL)]


Detailed Description

Matrix and Vector classes that support a block recursive structure capable of representing the natural structure from Finite Element discretisations.

The interface of our matrices is designed according to what they represent from a mathematical point of view. The vector classes are representations of vector spaces:

The matrix classes represent linear maps $A: V \mapsto W$ from vector space $V$ to vector space $W$ the recursive block structure of the matrix rows and columns immediately follows from the recursive block structure of the vectors representing the domain and range of the mapping, respectively:


Files

file  io.hh
 Some generic functions for pretty printing vectors and matrices.
file  matrixutils.hh
 Some handy generic functions for ISTL matrices.

Modules

 Block Recursive Iterative Kernels

Classes

class  Dune::BCRSMatrix< B, A >
 A sparse block matrix with compressed row storage. More...
class  Dune::BDMatrix< B, A >
 A block-diagonal matrix. More...
class  Dune::BlockVector< B, A >
 A vector of blocks with memory management. More...
class  Dune::Matrix< T, A >
 A generic dynamic matrix. More...
struct  Dune::CheckIfDiagonalPresent< blocklevel, l >
 Check whether the a matrix has diagonal values on blocklevel recursion levels. More...
class  Dune::VariableBlockVector< B, A >
 A Vector of blocks with different blocksizes. More...

Functions

void Dune::fill_row (std::ostream &s, int m, int width, int precision)
 print a row of zeros for a non-existing block
template<class M>
void Dune::print_row (std::ostream &s, const M &A, typename M::size_type I, typename M::size_type J, typename M::size_type therow, int width, int precision)
 print one row of a matrix
template<class K, int n, int m>
void Dune::print_row (std::ostream &s, const FieldMatrix< K, n, m > &A, typename FieldMatrix< K, n, m >::size_type I, typename FieldMatrix< K, n, m >::size_type J, typename FieldMatrix< K, n, m >::size_type therow, int width, int precision)
 print one row of a matrix, specialization for FieldMatrix
template<class K>
void Dune::print_row (std::ostream &s, const FieldMatrix< K, 1, 1 > &A, typename FieldMatrix< K, 1, 1 >::size_type I, typename FieldMatrix< K, 1, 1 >::size_type J, typename FieldMatrix< K, 1, 1 >::size_type therow, int width, int precision)
 print one row of a matrix, specialization for FieldMatrix<K,1,1>
template<class M>
void Dune::printmatrix (std::ostream &s, const M &A, std::string title, std::string rowtext, int width=10, int precision=2)
 Prints a generic block matrix.
template<class B, int n, int m, class A>
void Dune::printSparseMatrix (std::ostream &s, const BCRSMatrix< FieldMatrix< B, n, m >, A > &mat, std::string title, std::string rowtext, int width=3, int precision=2)
 Prints a BCRSMatrix with fixed sized blocks.
template<class FieldType, int rows, int cols>
void Dune::writeMatrixToMatlabHelper (const FieldMatrix< FieldType, rows, cols > &matrix, int rowOffset, int colOffset, std::ostream &s)
 Helper method for the writeMatrixToMatlab routine.
template<class MatrixType>
void Dune::writeMatrixToMatlab (const MatrixType &matrix, const std::string &filename)
 Writes sparse matrix in a Matlab-readable format.
template<class M>
int Dune::countNonZeros (const M &matrix)
 Get the number of nonzero fields in the matrix.


Function Documentation

template<class M>
int Dune::countNonZeros ( const M &  matrix  )  [inline]

Get the number of nonzero fields in the matrix.

This is not the number of nonzero blocks, but the number of non zero scalar entries (on blocklevel 1) if the matrix is viewed as a flat matrix.

For FieldMatrix this is simply the number of columns times the number of rows, for a BCRSMatrix<FieldMatrix<K,n,m>> this is the number of nonzero blocks time n*m.

template<class M>
void Dune::printmatrix ( std::ostream &  s,
const M &  A,
std::string  title,
std::string  rowtext,
int  width = 10,
int  precision = 2 
) [inline]

Prints a generic block matrix.

Bug:
Empty rows and columns are omitted by this method. (FlySpray #7)

References Dune::print_row().

template<class B, int n, int m, class A>
void Dune::printSparseMatrix ( std::ostream &  s,
const BCRSMatrix< FieldMatrix< B, n, m >, A > &  mat,
std::string  title,
std::string  rowtext,
int  width = 3,
int  precision = 2 
) [inline]

Prints a BCRSMatrix with fixed sized blocks.

Only the nonzero entries will be printed as matrix blocks together with their corresponding column index and all others will be omitted.

This might be preferable over printmatrix in the case of big sparse matrices with nonscalar blocks.

Parameters:
s The ostream to print to.
mat The matrix to print.
title The title for the matrix.
rowtext The text to prepend to each print out of a matrix row.
width The number of nonzero blocks to print in one line.
precision The precision to use when printing the numbers.

template<class MatrixType>
void Dune::writeMatrixToMatlab ( const MatrixType &  matrix,
const std::string &  filename 
) [inline]

Writes sparse matrix in a Matlab-readable format.

This routine writes the argument BCRSMatrix to a file with the name given by the filename argument. The file format is ASCII, with no header, and three data columns. Each row describes a scalar matrix entry and consists of the matrix row and column numbers (both counted starting from 1), and the matrix entry. Such a file can be read from Matlab using the command

         new_mat = spconvert(load('filename'));
       

References Dune::writeMatrixToMatlabHelper().

template<class FieldType, int rows, int cols>
void Dune::writeMatrixToMatlabHelper ( const FieldMatrix< FieldType, rows, cols > &  matrix,
int  rowOffset,
int  colOffset,
std::ostream &  s 
) [inline]

Helper method for the writeMatrixToMatlab routine.

This specialization for FieldMatrices ends the recursion

References Dune::writeMatrixToMatlabHelper().

Referenced by Dune::writeMatrixToMatlab(), and Dune::writeMatrixToMatlabHelper().


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