Indefinite matrices collected by Nick Gould, Yifan Hu, and Jennifer Scott. The GHS_indef and GHS_psdef collection includes matrices from the Matrix Market (math.nist.gov/MatrixMarket), Rutherford-Boeing collection (Duff, Grimes, and Lewis), the Parasol project (see below), Kumfert and Pothen, CUTE/CUTEr optimization test set, the UF sparse matrix collection (those are excluded here), Andy Wathen, Mario Arioli, Christian Damhaug, Alison Ramage, Anshul Gupta (Gupta's matrices are in the UF collection under the Gupta directory), Olaf Schenk (matrices from Olaf Schenk are located here, as well as in the existing Schenk_* directories), Miroslav Tuma, Maros and Meszaros, and the Dept. of Mathematical Modelling in DIAMO (Czech Republic). See ftp://ftp.numerical.rl.ac.uk/pub/matrices/symmetric/ for the GHS collection. NOTE: matrices can have upper-case or lower case matrix-type fields (rsa or RSA, for example). -------------------------------------------------------------------------------- bms3_2 matrix: Source: www.parallab.uib.no/parasol/data.html (matrix BMW3_2) Linear static analysis of a car body. Indefinite matrix. (MSC-CARBODY-220K) Order 227362 No. entries 5757996 -------------------------------------------------------------------------------- Matrices form Olaf Schenk: see the description in the Schenk_IBMNA directory, for the c-55 to c-72 matrices. -------------------------------------------------------------------------------- SIT100, K1_SAN, OLESNIKO, D_PRETOK, and TURON_M are from the Dept. of Mathematical Modelling in DIAMO, s.e., Straz pod Ralskem, Czech Republic. They represent fluid flow in porous media.