Unsymmetrized multifrontal LU factorization.

Amestoy, P. R. ; Puglisi, C.

Technical Information Center Oak Ridge Tennessee

关键词: Computer calculations;    Algorithms;    Factorization;    Matrices;    Fault tree analysis;   

RP-ID  :  DE2001776628

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

A well-known approach to compute the LU factorization of a general unsymmetric matrix bf A is to build the elimination tree associated with the pattern of the symmetric matrix A + A(sup T) 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 unsymmetry of the submatrices involved during the process 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.