%0 Generic %1 greif2015symildl %A Greif, Chen %A He, Shiwen %A Liu, Paul %D 2015 %K linearAlgebra %T SYM-ILDL: Incomplete $LDL^T$ Factorization of Symmetric Indefinite and Skew-Symmetric Matrices %U http://arxiv.org/abs/1505.07589 %X SYM-ILDL is a numerical software package that computes incomplete $LDL^T$ (or `ILDL') factorizations of symmetric indefinite and real skew-symmetric matrices. The core of the algorithm is a Crout variant of incomplete LU (ILU), originally introduced and implemented for symmetric matrices by Li and Saad, Crout versions of ILU factorization with pivoting for sparse symmetric matrices, Transactions on Numerical Analysis 20, pp. 75--85, 2005. Our code is economical in terms of storage and it deals with real skew-symmetric matrices as well, in addition to symmetric ones. The package is written in C++ and it is templated, open source, and includes a MATLAB interface. The code includes built-in RCM and AMD reordering, two equilibration strategies, threshold Bunch-Kaufman pivoting and rook pivoting, as well as a wrapper to MC64, a popular matching based equilibration and reordering algorithm. We also include two built-in iterative solvers: SQMR preconditioned with ILDL, or MINRES preconditioned with a symmetric positive definite preconditioner based on the ILDL factorization.

@misc{greif2015symildl, abstract = {SYM-ILDL is a numerical software package that computes incomplete $LDL^{T}$ (or `ILDL') factorizations of symmetric indefinite and real skew-symmetric matrices. The core of the algorithm is a Crout variant of incomplete LU (ILU), originally introduced and implemented for symmetric matrices by [Li and Saad, Crout versions of ILU factorization with pivoting for sparse symmetric matrices, Transactions on Numerical Analysis 20, pp. 75--85, 2005]. Our code is economical in terms of storage and it deals with real skew-symmetric matrices as well, in addition to symmetric ones. The package is written in C++ and it is templated, open source, and includes a MATLAB interface. The code includes built-in RCM and AMD reordering, two equilibration strategies, threshold Bunch-Kaufman pivoting and rook pivoting, as well as a wrapper to MC64, a popular matching based equilibration and reordering algorithm. We also include two built-in iterative solvers: SQMR preconditioned with ILDL, or MINRES preconditioned with a symmetric positive definite preconditioner based on the ILDL factorization.}, added-at = {2016-03-28T07:59:39.000+0200}, author = {Greif, Chen and He, Shiwen and Liu, Paul}, biburl = {https://www.bibsonomy.org/bibtex/217ac6136e5f6888c61b0a80cf6c7b2b0/pixor}, description = {[1505.07589] SYM-ILDL: Incomplete $LDL^{T}$ Factorization of Symmetric Indefinite and Skew-Symmetric Matrices}, interhash = {f6ebed7f7336dcb91a97b22cb739b953}, intrahash = {17ac6136e5f6888c61b0a80cf6c7b2b0}, keywords = {linearAlgebra}, note = {cite arxiv:1505.07589Comment: 19 pages, 3 figures}, timestamp = {2016-03-28T07:59:39.000+0200}, title = {SYM-ILDL: Incomplete $LDL^{T}$ Factorization of Symmetric Indefinite and Skew-Symmetric Matrices}, url = {http://arxiv.org/abs/1505.07589}, year = 2015 }