tag:blogger.com,1999:blog-593563533834706486.post6956903861444673612..comments2024-03-28T10:35:10.453-04:00Comments on Yet Another Math Programming Consultant: Network extractionErwin Kalvelagenhttp://www.blogger.com/profile/09496091402502236997noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-593563533834706486.post-30833626392846127532011-03-04T06:36:55.089-05:002011-03-04T06:36:55.089-05:00Thanks again for the upload.
I now have a fix so...Thanks again for the upload. <br /><br />I now have a fix so if you input a pure network then MOSEK should always discover it. You can see the result below. I will notify Michael at GAMS about it. You can talk to him about a new version.<br /><br /><br />Simplex network detection is started.<br />Number of network constraints: 630<br />Number of network variables : 67032<br />Simplex network detection is terminated.<br />Simplex network optimizer started.<br />Primal simplex network optimizer started.<br />Primal simplex network optimizer setup started.<br />Primal simplex network optimizer setup terminated.<br />Optimizer - solved problem : the primal<br />Optimizer - constraints : 630 variables : 67032<br />Optimizer - hotstart : no<br />ITER DEGITER(%) PFEAS DFEAS POBJ DOBJ TIME TOTTIME<br />0 0.00 0.00e+00 NA -0.0000000000e+00 NA 0.02 0.11<br />2096 0.00 0.00e+00 NA 2.6746955210e+02 NA 0.03 0.12<br />Primal simplex network optimizer terminated.<br />Simplex network optimizer terminated.<br />2096 0.00 0.00e+00 NA 2.6746955210e+02 NA 0.04 0.12<br />Primal simplex optimizer terminated.<br />Simplex optimizer terminated. Time: 0.14.<br />Optimizer terminated. Time: 0.16<br /><br />Solution summary<br /> Basic solution<br /> Problem status : PRIMAL_AND_DUAL_FEASIBLE<br /> Solution status : OPTIMAL<br /> Primal - objective: 2.6746955210e+02 eq. inf.: 0.00e+00 max bound inf.: 0.00e+00<br /> Dual - objective: 2.6746955210e+02 eq. inf.: 0.00e+00 max bound inf.: 0.00e+00Erling D. Andersenhttps://www.blogger.com/profile/07306894197500659436noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-66553053859202999632011-03-03T04:47:08.561-05:002011-03-03T04:47:08.561-05:00Thanks for the upload.Thanks for the upload.Erling D. Andersenhttps://www.blogger.com/profile/07306894197500659436noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-88130251535060169562011-03-01T09:50:07.379-05:002011-03-01T09:50:07.379-05:00I have uploaded files demonstrating this here:
K13...I have uploaded files demonstrating this here:<br /><a href="http://amsterdamoptimization.com/models/assign/K13.gms" rel="nofollow">K13.gms</a> and <a href="http://amsterdamoptimization.com/models/assign/K14.gms" rel="nofollow">K14.gms</a>. Good luck!Erwin Kalvelagenhttps://www.blogger.com/profile/09496091402502236997noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-49455557989222281312011-03-01T08:29:33.222-05:002011-03-01T08:29:33.222-05:00I have learned from Michael Bussieck that you have...I have learned from Michael Bussieck that you have newest version, so it is not the obj. issue.<br /><br />I think there is a bug in the code but without seeing example data it is close to impossible to fix.Erling D. Andersenhttps://www.blogger.com/profile/07306894197500659436noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-15375382277919933372011-03-01T02:33:49.356-05:002011-03-01T02:33:49.356-05:00MOSEK support here.
The GAMS quirk you talk about...MOSEK support here.<br /><br />The GAMS quirk you talk about might very well be the issue. Michael Bussieck is working on a new MOSEK interface. I think that might solve it. At least it would be interesting to check if the new interface also has the issue.<br /><br />You are of course also welcome to contact MOSEK support. If we can get the problem we might be able to do something about it.Erling D. Andersenhttps://www.blogger.com/profile/07306894197500659436noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-84629482459425104842011-02-28T21:41:40.346-05:002011-02-28T21:41:40.346-05:00Its a pure transportation problem.Its a pure transportation problem.Erwin Kalvelagenhttps://www.blogger.com/profile/09496091402502236997noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-51849325684797282412011-02-28T09:45:46.781-05:002011-02-28T09:45:46.781-05:00Have you tried to run on a exported mps file ? You...Have you tried to run on a exported mps file ? You will have to contact mosek support for a better reply, since I do not work for mosek. Are these models pure network or with side constraints ?Bo Jensenhttps://www.blogger.com/profile/10533779186894174073noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-61707459250325035982011-02-28T09:25:38.306-05:002011-02-28T09:25:38.306-05:00That does not help. I suspect the link does not pr...That does not help. I suspect the link does not properly substitute out the objective variable (a GAMS quirk) before passing the model to Mosek.Erwin Kalvelagenhttps://www.blogger.com/profile/09496091402502236997noreply@blogger.comtag:blogger.com,1999:blog-593563533834706486.post-5858184333356903832011-02-28T09:12:41.696-05:002011-02-28T09:12:41.696-05:00I would try switching off presolve and scaling.I would try switching off presolve and scaling.Bo Jensenhttps://www.blogger.com/profile/10533779186894174073noreply@blogger.com