1%%MatrixMarket matrix coordinate real general 2%------------------------------------------------------------------------------- 3% UF Sparse Matrix Collection, Tim Davis 4% http://www.cise.ufl.edu/research/sparse/matrices/LPnetlib/lpi_itest6 5% name: LPnetlib/lpi_itest6 6% [Netlib LP problem itest6: minimize c'*x, where Ax=b, lo<=x<=hi] 7% id: 720 8% date: 1991 9% author: J. Chinneck, E. Dravnieks 10% ed: J. Chinneck 11% fields: title name A b id aux kind date author ed notes 12% aux: c lo hi z0 13% kind: linear programming problem 14%------------------------------------------------------------------------------- 15% notes: 16% An infeasible Netlib LP problem, in lp/infeas. For more information 17% send email to netlib@ornl.gov with the message: 18% 19% send index from lp 20% send readme from lp/infeas 21% 22% The lp/infeas directory contains infeasible linear programming test problems 23% collected by John W. Chinneck, Carleton Univ, Ontario Canada. The following 24% are relevant excerpts from lp/infeas/readme (by John W. Chinneck): 25% 26% In the following, IIS stands for Irreducible Infeasible Subsystem, a set 27% of constraints which is itself infeasible, but becomes feasible when any 28% one member is removed. Isolating an IIS from within the larger set of 29% constraints defining the model is one analysis approach. 30% 31% PROBLEM DESCRIPTION 32% ------------------- 33% 34% ITEST6, ITEST2: very small problems having numerous clustered IISs. 35% These match problems 1 and 2, respectively, in Chinneck and Dravnieks 36% [1991]. Contributors: J.W. Chinneck and E.W. Dravnieks, Carleton 37% University. 38% 39% Name Rows Cols Nonzeros Bounds Notes 40% itest6 12 8 23 41% 42% REFERENCES 43% ---------- 44% 45% J.W. Chinneck and E.W. Dravnieks (1991). "Locating Minimal Infeasible 46% Constraint Sets in Linear Programs", ORSA Journal on Computing, Volume 47% 3, No. 2. 48% 49%------------------------------------------------------------------------------- 5011 17 29 511 1 1 522 2 1 533 3 1 544 4 -1 555 5 -1 566 6 1 577 7 -1 588 8 1 5911 9 -1 602 10 1 614 11 -1 625 11 -1 639 11 1 6410 11 1 6511 11 1 661 12 .8 674 12 1 686 12 1 699 12 -.05 7010 12 -.04 711 13 1 725 13 1 7310 13 -.05 747 14 -3 758 14 .5 763 15 2 778 15 .6 787 16 1 793 17 -1 80