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added SparseSetter doc

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Gael Guennebaud 2008-08-22 11:19:12 +00:00
parent a814ebe180
commit 95db4e9841
1 changed files with 36 additions and 0 deletions
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36
Eigen/src/Sparse/SparseSetter.h
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@ -29,6 +29,42 @@ template<typename MatrixType, int AccessPattern,
int IsSupported = ei_support_access_pattern<MatrixType,AccessPattern>::ret>
struct ei_sparse_setter_selector;
/** \class SparseSetter
*
* Goal: provides a unified API to fill/update a dense or sparse matrix.
*
* Usage:
* \code
* {
* SparseSetter<MatrixType, RandomAccessPattern> w(m);
* for (...) w->coeffRef(rand(),rand()) = rand();
* }
* \endcode
*
* In the above example we want to fill a matrix m (could be a SparseMatrix or whatever other matrix type)
* in a random fashion (whence the RandomAccessPattern). Internally, if \a MatrixType supports random writes
* then \c w behaves as a pointer to m, and m is filled directly. Otherwise, a temporary matrix supporting
* random writes is created and \c w behaves as a pointer to this temporary object. When the object \c w
* is deleted (at the end of the block), then the temporary object is assigned to the matrix m.
*
* So far we can distinghished 4 types of access pattern:
* - FullyCoherentAccessPattern (if col major, i+j*rows must increase)
* - InnerCoherentAccessPattern (if col major, i must increase for each column j)
* - OuterCoherentAccessPattern (if col major, the column j is set in a random order, but j must increase)
* - RandomAccessPattern
*
* See the wiki for more details.
*
* The template class ei_support_access_pattern is used to determine the type of the temporary object (which
* can be a reference to \a MatrixType if \a MatrixType support \a AccessPattern)
*
* Currently only the RandomAccessPattern seems to work as expected.
*
* \todo define the API for each kind of access pattern
* \todo allows both update and set modes (set start a new matrix)
* \todo implement the OuterCoherentAccessPattern
*
*/
template<typename MatrixType,
int AccessPattern,
typename WrapperType = typename ei_sparse_setter_selector<MatrixType,AccessPattern>::type>