Title
Dynamic Supernodes in Sparse Cholesky Update/Downdate and Triangular Solves
Abstract
The supernodal method for sparse Cholesky factorization represents the factor L as a set of supernodes, each consisting of a contiguous set of columns of L with identical nonzero pattern. A conventional supernode is stored as a dense submatrix. While this is suitable for sparse Cholesky factorization where the nonzero pattern of L does not change, it is not suitable for methods that modify a sparse Cholesky factorization after a low-rank change to A (an update/downdate, Ā = A ± WWT). Supernodes merge and split apart during an update/downdate. Dynamic supernodes are introduced which allow a sparse Cholesky update/downdate to obtain performance competitive with conventional supernodal methods. A dynamic supernodal solver is shown to exceed the performance of the conventional (BLAS-based) supernodal method for solving triangular systems. These methods are incorporated into CHOLMOD, a sparse Cholesky factorization and update/downdate package which forms the basis of x = A\b MATLAB when A is sparse and symmetric positive definite.
Year
DOI
Venue
2009
10.1145/1462173.1462176
ACM Trans. Math. Softw.
Keywords
Field
DocType
conventional supernodal method,factor l,sparse matrices,sparse cholesky update,sparse cholesky factorization,linear equations,dynamic supernodes,triangular solves,dynamic supernodal solver,downdate package,conventional supernode,supernodal method,contiguous set,cholesky factorization,algorithms
Incomplete Cholesky factorization,Positive-definite matrix,Matrix decomposition,Minimum degree algorithm,Algorithm,Solver,Supernode,Sparse matrix,Mathematics,Cholesky decomposition
Journal
Volume
Issue
ISSN
35
4
0098-3500
Citations 
PageRank 
References 
28
2.12
20
Authors
2
Name
Order
Citations
PageRank
TIMOTHY A. DAVIS11447144.19
William W. Hager21603214.67