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Mark Thomas edited comment on MATH-351 at 3/31/10 6:44 PM: ----------------------------------------------------------- Good catch. Not sure how I missed this. I'm still getting an UnboundedSolutionException, even after I set the coefficients all to 1, however. Note that I'm still using the 2.0 code which was noted above to have a bug in it. Are you using 2.1? Thanks Jurgen! --Mark was (Author: thomamark): Good catch--not sure how I missed this. I'm still getting an UnboundedSolutionException, even after I set the coefficients all to 1, however. Note that I'm still using the 2.0 code which was noted above to have a bug in it--are you using 2.1? Thanks Jurgen! --Mark > SimplexSolver fails to solve feasible problem instance > ------------------------------------------------------- > > Key: MATH-351 > URL: https://issues.apache.org/jira/browse/MATH-351 > Project: Commons Math > Issue Type: Bug > Affects Versions: 2.0 > Environment: Windows Vista Home Premium Version 6.0 Service Pack 1, > Build 6001 > Reporter: Mark Thomas > Fix For: 2.1 > > Attachments: SimplexFail.xlsx, TestSimplexFail.java > > > SimplexSolver throws an UnboundedSolutionException on a problem instance I > can optimally solve with Excel's Solver. I've kept the parameters between the > two programs the same as far as I can tell (i.e. both have a > precision/epsilon value of 1e-6 and a maxIterations value of 1000). I will > attach a JUnit test with an example problem on which SimplexSolver fails. I > will also attach an Excel spreadsheet wtih the same data and successful > Solver setup in place. > I don't know a whole lot about linear programming or Simplex, but the problem > I'm attempting to solve does appear to have a fairly sparse coefficient > matrix, which may be part of the problem. > It's surprisingly difficult to find a Java-based linear programming library, > so I was ecstatic when I found this. Let me know how I can help! > Thanks! -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.