-------- Forwarded Message -------- From: Melih Ozlen <[email protected]> To: [email protected] Subject: Possible GLPK - Sensitivity Report Bug Date: Fri, 2 Sep 2011 11:00:04 +1000
Hi, I'm not sure whether if it's an already reported bug (or maybe it's not a bug either), I'm teaching GLPK as a part of my linear programming subject, as a part of our discussion we need to get the sensitivity reports, they show the right values for most parts but fail to show the right range values for certain things, specifically, * when there is slack/surplus within a constraint, it returns an activity range not including the initial value, so is misleading for inexperienced students as the range should actually be between the initial value and the current level of activity, objective value at break points also returns misleading values based on this, they should be equal to the initial optimal value, * for a nonbasic variable the objective value at break points should be equal to the initial optimal value, however it returns two other values, again misleading for inexperienced students, * and as a suggestion for improvement is it possible to have no activity ranges for columns, and no objective coefficient ranges for rows, again it can be quite misleading for inexperienced students, I'm not sending any problem instances as these happen for all problems in general, but please let me know if you need an instance. If they actually are bugs or areas that needs to be improved I would love to help you as much as I can, please let me know how, Regards, melih _______________________________________________ Bug-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/bug-glpk
