GAMS World Forum

Hello community team, I have tried to write a scheduling problem which has been described by Sousa and Wolsey in machine scheduling. I'm going to use two different approaches to write my code. First, using the special syntax into the constraint and second, create dynamic sets. The following code des...

Dear community team, I have tried to solve a scheduling model. I would like to use a warm start to solve my problem because The model takes much time to solve optimally even for a small set of given data. The model statistic and what I'm looking for are as follows. The original model, a small instan...

Dear Fred,

Thanks so much for your reply. Would you say, is there any way to get a (.MPS) like format from GAMS, please?

Regards
Abbas

Dear community, I have tried to use convert facility to write a (.MPS) file from an NLP solver. The code is as follows: model Mark_cut / all /; *** Modifications * choose convert as solver option nlp = convert; ** write convert option file $echo fixedmps Mark_cut.mps > convert.opt ** instruct conver...

Dear community team, I'm trying to use Neos/GAMS to solve an optimization problem. I will need to get a MPS file from the model. With using GAMS IDE it is easy to use an option file to get it but, it needs a licence file for large models. My question is, is there any way to get an MPS file using the...

Dear Fred, Thanks for your comment. I was trying to solve the attached example using GAMS/Kestrel via GAMS studio 28.1.0. When I solve the model log file is as follows: --- Job GAMS..Kestrel.gms Start 08/20/19 10:29:58 28.1.0 r5b48834 WEX-WEI x86 64bit/MS Windows --- GAMS Parameters defined Input C:...

Dear support team, I'm trying to run the GAMS model using neos-server. I wrote the following code in the GAMS studio: Option mip=kestrel; sequence.optfile=1; $onecho > kestrel.opt kestrel_solver cplex neos_server www.neos-server.org:3333 $offecho But it doesn't work. I was wondering if, how can I co...

Hello support team, I have worked on the MIP model that contains the chance constraints. The constraint is: probability_cons.. prob[sum(j, a(j)*x(j)) =l= b] =g= beta; Where a(j) and b are given parameters and beta is the probability. I was wondering if, you say that, is there any efficient way to wr...

Hello support team,

Would you please, say that is there any way (or any example) to read an "MPS/LP" file in the GAMS Java API and get output in the specific format? If so, could you advise me, please?

Regards
Omidi. A

Dear Fred, Thanks for your useful comment. As per your advice, I try to use a medium scale problem using both binary and SOS1 variables. The results and solving time are the same. I think using of SOS1 does not improve solving time (in my problem). Unfortunately, I can not understand why GUROBI (Jav...