On the complexity of sparse QR and LU factorization of finite-element matrices

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · SIAM J. Sci. Stat. Comput.; (United States)

DOI:https://doi.org/10.1137/0909057· OSTI ID:6637443

George, A; Ng, E

Let A be an n x n sparse nonsingular matrix derived from a two-dimensional finite-element mesh. If the matrix is symmetric and positive definite, and a nested dissection ordering is used, then the Cholesky factorization of A can be computed using O(n/sup 3/2/) arithmetic operations, and the number of nonzeros in the Cholesky factor is O(n log n). In this article the authors show that the same complexity bounds can be attained when A is nonsymmetric and indefinite, and either Gaussian elimination with partial pivoting or orthogonal factorization is applied. Numerical experiments for a sequence of irregular mesh problems are provided.

• Research Organization: Oak Ridge National Lab., Oak Ridge, TN (US)
• OSTI ID: 6637443
• Journal Information: SIAM J. Sci. Stat. Comput.; (United States), Journal Name: SIAM J. Sci. Stat. Comput.; (United States) Vol. 9:5; ISSN SIJCD
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
990200* -- Mathematics & Computers
COMPUTER CALCULATIONS
DATA
EXPERIMENTAL DATA
FACTORIZATION
FINITE ELEMENT METHOD
INFORMATION
MATRICES
NUMERICAL DATA
NUMERICAL SOLUTION
TWO-DIMENSIONAL CALCULATIONS