Maintaining LU factors of a general sparse matrix

Philip E. Gill, Walter Murray, Michael A. Saunders, Matgaret H. Wright

Research output: Contribution to journalArticlepeer-review


We describe a set of procedures for computing and updating an LU factorization of a sparse matrix A, where A may be square (possibly singular) or rectangular. The procedures include a Markowitz factorization and a Bartels-Golub update, similar to those of Reid (1976, 1982). The updates provided are addition, deletion or replacement of a row or column of A, and rank-one modification. (Previously, column replacement has been the only update available.). Various design features of the implementation (LUSOL) are described, and computational comparisons are made with the LA05 and MA28 packages of Reid (1976) and Duff (1977).

Original languageEnglish (US)
Pages (from-to)239-270
Number of pages32
JournalLinear Algebra and Its Applications
Issue numberC
StatePublished - Apr 1987

ASJC Scopus subject areas

  • Algebra and Number Theory
  • Numerical Analysis
  • Geometry and Topology
  • Discrete Mathematics and Combinatorics


Dive into the research topics of 'Maintaining LU factors of a general sparse matrix'. Together they form a unique fingerprint.

Cite this