permutation(3)
NAME
permutation -- permutation matrix
DESCRIPTION
This class implements a permutation matrix.
Permutation matrix are used in factorization
implementation for optimizing the skyline format,
as used by the implementation of the
ssk class (see ssk(3)).
- Let a be a square invertible matrix in csr format
(see csr(3)): - csr<double> a;
- We get the optimal Gibbs permutation matrix using
Gibbs, Pooles and Stockmeyer renumbering algorithm by:
permutation p = gibbs(a);
IMPLEMENTATION
class permutation : public Array<std::vector<int>::size_type> {
public:
- // typedefs:
- typedef Array<int>::size_type size_type;
typedef Array<int>::difference_type difference_type; - // allocators/deallocators:
explicit permutation (size_type n = 0);- };
template<class T>
permutation gibbs (const csr<T>& a);