Français Anglais
Accueil Annuaire Plan du site
Accueil > Evenements > Séminaires
Séminaire du LRI
Lazy BLAS-3 Reduction to Banded Upper Triangular
Gary Howell

15 September 2011, 10h30 - 15 September 2011, 12h00
Salle/Bat : 455/PCRI-N
Contact :

Activités de recherche :

Résumé :
In a "Lazy" or "Just in Time" decomposition algorithm, updates are deferred until columns or rows (row blocks .. column blocks) are to be eliminated. A one-sided example is the GMRES algorithm (corresponding to orthogonal reduction to Hessenberg form). Here we consider reduction by Householder transformations to bidiagonal or to banded triangular form. Because the only accesses to original matrix are extraction of blocks and mutliplication by it, the lazy algorithm is easy to apply to sparse matrices. For a reduction to banded form, almost all the operations are BLAS-3. One use is determining a set of largest singular values of a sparse matrix.

Pour en savoir plus :
Séminaires
Pierre Andrieu - Agrégation de classements pour le
Thursday 21 October 2021 - 00h00
Salle : 435 - PCRI-N
.............................................

A counting argument for graph colouring
Théorie des graphes
Friday 08 October 2021 - 11h00
Salle : 445 - PCRI-N
Francois Pirot .............................................

Demographic reconstruction from paleogenomes of th
Thursday 25 February 2021 - 14h00
Salle : 435 - PCRI-N
Nina Marchi .............................................

A Graph-based Similarity Approach to Classify Recu
Thursday 18 February 2021 - 14h00
Salle : 435 - PCRI-N
Coline Gianfrotta .............................................

"Answer Set Programming for computing constraints-
Thursday 04 February 2021 - 14h00
Salle : 435 - PCRI-N
Maxime Mahout .............................................