Preordering saddle-point systems for sparse LDLT factorization without pivoting

Autor: Sangye Lungten, Jennifer A. Scott, Wil H. A. Schilders
Přispěvatelé: Center for Analysis, Scientific Computing & Appl.
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Numerical Linear Algebra with Applications, 25(5):e2173. Wiley
ISSN: 1070-5325
Popis: This paper focuses on efficiently solving large sparse symmetric indefinite systems of linear equations in saddle-point form using a fill-reducing ordering technique with a direct solver. Row and column permutations partition the saddle-point matrix into a block structure constituting a priori pivots of order 1 and 2. The partitioned matrix is compressed by treating each nonzero block as a single entry, and a fill-reducing ordering is applied to the corresponding compressed graph. It is shown that, provided the saddle-point matrix satisfies certain criteria, a block LDLT factorization can be computed using the resulting pivot sequence without modification. Numerical results for a range of problems from practical applications using a modern sparse direct solver are presented to illustrate the effectiveness of the approach.
Databáze: OpenAIRE