On Tue, Jul 29, 2008 at 3:53 PM, Andrew Makhorin <[EMAIL PROTECTED]> wrote: >>> Probably this happens because your instance is not well conditioned, >>> so due to excessive round-off errors the presolved lp is unbounded >>> while the original lp is not. >> What does "not well conditioned" mean? What can I do about it? > > Ill-conditioning means, roughly speaking, that small changes in the > problem data lead to large changes in the solution. > > Your instance in fact is ill conditioned....
Could anyone perhaps give me some literature pointers (preferrably freely available on the net) on how to achieve this "well-conditioned" situation, or some examples? I was playing a bit with scaling variables and it seems to improve things a bit, but I am probably reinventing the wheel. Sorry if my question is a bit off topic. Thanks Marcin _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
