Search found 21 matches

by abb.omidi
2 days ago
Forum: Modeling
Topic: GAMS/convert solver
Replies: 2
Views: 61

Re: GAMS/convert solver

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
by abb.omidi
5 days ago
Forum: Modeling
Topic: GAMS/convert solver
Replies: 2
Views: 61

GAMS/convert solver

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...
by abb.omidi
1 week ago
Forum: Tools
Topic: Get a MPS file using NEOS/GAMS web interface
Replies: 0
Views: 113

Get a MPS file using NEOS/GAMS web interface

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...
by abb.omidi
1 month ago
Forum: Modeling
Topic: Connecting GAMS 28.1.0 to neos server
Replies: 3
Views: 160

Re: Connecting GAMS 28.1.0 to neos server

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:...
by abb.omidi
1 month ago
Forum: Modeling
Topic: Connecting GAMS 28.1.0 to neos server
Replies: 3
Views: 160

Connecting GAMS 28.1.0 to neos server

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...
by abb.omidi
2 months ago
Forum: Modeling
Topic: Modeling the chance constraints
Replies: 0
Views: 83

Modeling the chance constraints

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...
by abb.omidi
4 months ago
Forum: API
Topic: Read a MPS/LP file in Java
Replies: 3
Views: 423

Read a MPS/LP file in Java

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
by abb.omidi
4 months ago
Forum: Modeling
Topic: Using SOS type_1 constraint
Replies: 2
Views: 224

Re: Using SOS type_1 constraint

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...
by abb.omidi
4 months ago
Forum: Modeling
Topic: Using SOS type_1 constraint
Replies: 2
Views: 224

Using SOS type_1 constraint

Dear support team, I was trying to solve a scheduling model using GAMS/Gurobi. The snippet code is: Binary variable x(i,k); Equations c1,c2; c1(k).. sum(i, x(i,k)) =e= 1; c2(i).. sum(k, x(i,k)) =e= 1; Using the binary variables, the model has solved optimally. I have used SOS type_1 variables instea...
by abb.omidi
5 months ago
Forum: Modeling
Topic: Lazy constraints
Replies: 4
Views: 369

Re: Lazy constraints

Dear Fred,

Thanks so much for your help.
I can do it and it works fine.

Regards
Omidi. A