Abstract de la publi numéro 2366
A well known approach to computing the LU factorization of
a general unsymmetric matrix A
is to build the elimination tree associated with the pattern of
the symmetric matrix A + AT and
use it as a computational graph to drive the numerical
factorization. This approach,
although very efficient on a large range of unsymmetric matrices,
does not capture the unsymmetric structure of the matrices.
We introduce a new algorithm which detects and exploits
the structural asymmetry of the submatrices involved during
the processing of the elimination tree.
We show that, with the new algorithm,
significant gains both in memory and in
time to perform the factorization can be obtained.