DUNE PDELab (2.8)
A block-tridiagonal matrix. More...
#include <dune/istl/btdmatrix.hh>
Public Types | |
using | field_type = typename Imp::BlockTraits< B >::field_type |
export the type representing the field | |
typedef B | block_type |
export the type representing the components | |
typedef A | allocator_type |
export the allocator type | |
typedef A::size_type | size_type |
implement row_type with compressed vector More... | |
enum | BuildMode |
we support two modes | |
typedef Imp::CompressedBlockVectorWindow< B, std::allocator< B > > | row_type |
implement row_type with compressed vector | |
typedef ::Dune::CompressionStatistics< size_type > | CompressionStatistics |
The type for the statistics object returned by compress() | |
typedef RealRowIterator< row_type > | iterator |
The iterator over the (mutable matrix rows. | |
typedef Iterator | RowIterator |
rename the iterators for easier access | |
typedef row_type::Iterator | ColIterator |
Iterator for the entries of each row. | |
typedef RealRowIterator< const row_type > | const_iterator |
The const iterator over the matrix rows. | |
typedef ConstIterator | ConstRowIterator |
rename the const row iterator for easier access | |
typedef row_type::ConstIterator | ConstColIterator |
Const iterator to the entries of a row. | |
Public Member Functions | |
BTDMatrix () | |
Default constructor. | |
void | setSize (size_type size) |
Resize the matrix. Invalidates the content! | |
BTDMatrix & | operator= (const BTDMatrix &other) |
assignment | |
BTDMatrix & | operator= (const field_type &k) |
assignment from scalar | |
template<class V > | |
void | solve (V &x, const V &rhs) const |
Use the Thomas algorithm to solve the system Ax=b in O(n) time. More... | |
row_type & | operator[] (size_type i) |
random access to the rows | |
const row_type & | operator[] (size_type i) const |
same for read only access | |
Iterator | begin () |
Get iterator to first row. | |
ConstIterator | begin () const |
Get const iterator to first row. | |
Iterator | end () |
Get iterator to one beyond last row. | |
ConstIterator | end () const |
Get const iterator to one beyond last row. | |
Iterator | beforeEnd () |
ConstIterator | beforeEnd () const |
Iterator | beforeBegin () |
ConstIterator | beforeBegin () const |
void | setBuildMode (BuildMode bm) |
Sets the build mode of the matrix. More... | |
void | setSize (size_type rows, size_type columns, size_type nnz=0) |
Set the size of the matrix. More... | |
void | setImplicitBuildModeParameters (size_type _avg, double compressionBufferSize) |
Set parameters needed for creation in implicit build mode. More... | |
CreateIterator | createbegin () |
get initial create iterator | |
CreateIterator | createend () |
get create iterator pointing to one after the last block | |
size_type | getrowsize (size_type i) const |
get current number of indices in row i | |
void | incrementrowsize (size_type i, size_type s=1) |
increment size of row i by s (1 by default) | |
void | setIndices (size_type row, It begin, It end) |
Set all column indices for row from the given iterator range. More... | |
B & | entry (size_type row, size_type col) |
Returns reference to entry (row,col) of the matrix. More... | |
CompressionStatistics | compress () |
Finishes the buildstage in implicit mode. More... | |
BCRSMatrix & | operator*= (const field_type &k) |
vector space multiplication with scalar | |
BCRSMatrix & | operator/= (const field_type &k) |
vector space division by scalar | |
BCRSMatrix & | operator+= (const BCRSMatrix &b) |
Add the entries of another matrix to this one. More... | |
BCRSMatrix & | operator-= (const BCRSMatrix &b) |
Subtract the entries of another matrix from this one. More... | |
BCRSMatrix & | axpy (field_type alpha, const BCRSMatrix &b) |
Add the scaled entries of another matrix to this one. More... | |
void | mv (const X &x, Y &y) const |
y = A x | |
void | umv (const X &x, Y &y) const |
y += A x | |
void | mmv (const X &x, Y &y) const |
y -= A x | |
void | usmv (F &&alpha, const X &x, Y &y) const |
y += alpha A x | |
void | mtv (const X &x, Y &y) const |
y = A^T x | |
void | umtv (const X &x, Y &y) const |
y += A^T x | |
void | mmtv (const X &x, Y &y) const |
y -= A^T x | |
void | usmtv (const field_type &alpha, const X &x, Y &y) const |
y += alpha A^T x | |
void | umhv (const X &x, Y &y) const |
y += A^H x | |
void | mmhv (const X &x, Y &y) const |
y -= A^H x | |
void | usmhv (const field_type &alpha, const X &x, Y &y) const |
y += alpha A^H x | |
FieldTraits< field_type >::real_type | frobenius_norm2 () const |
square of frobenius norm, need for block recursion | |
FieldTraits< field_type >::real_type | frobenius_norm () const |
frobenius norm: sqrt(sum over squared values of entries) | |
FieldTraits< ft >::real_type | infinity_norm () const |
infinity norm (row sum norm, how to generalize for blocks?) | |
FieldTraits< ft >::real_type | infinity_norm () const |
infinity norm (row sum norm, how to generalize for blocks?) | |
FieldTraits< ft >::real_type | infinity_norm_real () const |
simplified infinity norm (uses Manhattan norm for complex values) | |
FieldTraits< ft >::real_type | infinity_norm_real () const |
simplified infinity norm (uses Manhattan norm for complex values) | |
size_type | N () const |
number of rows (counted in blocks) | |
size_type | M () const |
number of columns (counted in blocks) | |
size_type | nonzeroes () const |
number of blocks that are stored (the number of blocks that possibly are nonzero) | |
BuildStage | buildStage () const |
The current build stage of the matrix. | |
BuildMode | buildMode () const |
The currently selected build mode of the matrix. | |
bool | exists (size_type i, size_type j) const |
return true if (i,j) is in pattern | |
Static Public Attributes | |
static constexpr auto | blocklevel = blockLevel<B>()+1 |
increment block level counter | |
Protected Member Functions | |
void | setColumnPointers (ConstRowIterator row) |
Copy row sizes from iterator range starting at row and set column index pointers for all rows. More... | |
void | setDataPointers () |
Set data pointers for all rows. More... | |
void | copyWindowStructure (const BCRSMatrix &Mat) |
Copy the window structure from another matrix. | |
void | deallocate (bool deallocateRows=true) |
deallocate memory of the matrix. More... | |
void | allocate (size_type rows, size_type columns, size_type allocationSize, bool allocateRows, bool allocate_data) |
Allocate memory for the matrix structure. More... | |
void | implicit_allocate (size_type _n, size_type _m) |
organizes allocation implicit mode calculates correct array size to be allocated and sets the the window pointers to their correct positions for insertion. internally uses allocate() for the real allocation. | |
Detailed Description
class Dune::BTDMatrix< B, A >
A block-tridiagonal matrix.
- Todo:
- It would be safer and more efficient to have a real implementation of a block-tridiagonal matrix and not just subclassing from BCRSMatrix. But that's quite a lot of work for that little advantage.
Member Typedef Documentation
◆ size_type
typedef A::size_type Dune::BTDMatrix< B, A >::size_type |
implement row_type with compressed vector
The type for the index access and the size
Member Function Documentation
◆ allocate()
|
inlineprotectedinherited |
Allocate memory for the matrix structure.
Sets the number of rows and columns of the matrix and allocates the memory needed for the storage of the matrix entries.
- Warning
- After calling this methods on an already allocated (and probably setup matrix) results in all the structure and data being lost. Please call deallocate() before calling allocate in this case.
- Parameters
-
row The number of rows the matrix should contain. columns the number of columns the matrix should contain. allocationSize The number of nonzero entries the matrix should hold (if omitted defaults to 0). allocateRow Whether we have to allocate the row pointers, too. (Defaults to true)
◆ axpy()
|
inlineinherited |
Add the scaled entries of another matrix to this one.
Matrix axpy operation: *this += alpha * b
- Parameters
-
alpha Scaling factor. b The matrix to add to this one. Its sparsity pattern has to be subset of the sparsity pattern of this matrix.
◆ beforeBegin() [1/2]
|
inlineinherited |
- Returns
- an iterator that is positioned before the first row of the matrix.
◆ beforeBegin() [2/2]
|
inlineinherited |
- Returns
- an iterator that is positioned before the first row of the matrix.
◆ beforeEnd() [1/2]
|
inlineinherited |
- Returns
- an iterator that is positioned before the end iterator of the rows, i.e. at the last row.
◆ beforeEnd() [2/2]
|
inlineinherited |
- Returns
- an iterator that is positioned before the end iterator of the rows. i.e. at the last row.
◆ compress()
|
inlineinherited |
Finishes the buildstage in implicit mode.
Performs compression of index and data arrays with linear complexity in the number of nonzeroes.
After calling this method, the matrix is in the built state and no more entries can be added.
- Returns
- An object with some statistics about the compression for future optimization.
◆ deallocate()
|
inlineprotectedinherited |
deallocate memory of the matrix.
- Parameters
-
deallocateRows Whether we have to deallocate the row pointers, too. If false they will not be touched. (Defaults to true).
◆ entry()
|
inlineinherited |
Returns reference to entry (row,col) of the matrix.
This method can only be used when the matrix is in implicit building mode.
A reference to entry (row, col) of the matrix is returned. If entry (row, col) is accessed for the first time, it is created on the fly.
This method can only be used while building the matrix, after compression operator[] gives a much better performance.
◆ operator+=()
|
inlineinherited |
Add the entries of another matrix to this one.
- Parameters
-
b The matrix to add to this one. Its sparsity pattern has to be subset of the sparsity pattern of this matrix.
◆ operator-=()
|
inlineinherited |
Subtract the entries of another matrix from this one.
- Parameters
-
b The matrix to subtract from this one. Its sparsity pattern has to be subset of the sparsity pattern of this matrix.
◆ setBuildMode()
|
inlineinherited |
Sets the build mode of the matrix.
- Parameters
-
bm The build mode to use.
◆ setColumnPointers()
|
inlineprotectedinherited |
Copy row sizes from iterator range starting at row and set column index pointers for all rows.
This method does not modify the data pointers, as those are set only after building the pattern (to allow for a delayed allocation).
◆ setDataPointers()
|
inlineprotectedinherited |
Set data pointers for all rows.
This method assumes that column pointers and row sizes have been correctly set up by a prior call to setColumnPointers().
◆ setImplicitBuildModeParameters()
|
inlineinherited |
Set parameters needed for creation in implicit build mode.
Use this method before setSize() to define storage behaviour of a matrix in implicit build mode
- Parameters
-
_avg expected average number of entries per row compressionBufferSize fraction of _n*_avg which is expected to be needed for elements that exceed _avg entries per row.
◆ setIndices()
|
inlineinherited |
Set all column indices for row from the given iterator range.
The iterator range has to be of the same length as the previously set row size. The entries in the iterator range do not have to be in any particular order, but must not contain duplicate values.
Calling this method overwrites any previously set column indices!
◆ setSize()
|
inlineinherited |
Set the size of the matrix.
Sets the number of rows and columns of the matrix and allocates the memory needed for the storage of the matrix entries.
- Warning
- After calling this methods on an already allocated (and probably setup matrix) results in all the structure and data being deleted. I.~e. one has to setup the matrix again.
- Parameters
-
rows The number of rows the matrix should contain. columns the number of columns the matrix should contain. nnz The number of nonzero entries the matrix should hold (if omitted defaults to 0). Must be omitted in implicit mode.
◆ solve()
|
inline |
Use the Thomas algorithm to solve the system Ax=b in O(n) time.
- Exceptions
-
ISTLError if the matrix is singular
References Dune::BCRSMatrix< B, std::allocator< B > >::N().
The documentation for this class was generated from the following file:
- dune/istl/btdmatrix.hh
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