Loading
Cookies help us deliver our services. By using our services, you agree to our use of cookies. Learn more

crowdAI is shutting down - please read our blog post for more information

Train Schedule Optimisation Challenge

Optimizing train schedules


Completed
209
Submissions
444
Participants
29670
Views

cplex

Posted by Michael18 about 1 year ago

can I use cplex for this problem

Posted by jordiju  about 1 year ago |  Quote

I see you already got an answer on github, thanks Sebastian. For the record also here: Yes, you can. https://www.crowdai.org/topics/accepted-commercial-solver-platforms/discussion

Posted by hur  about 1 year ago |  Quote

can we use AMPL to interface with cplex/gurobi as well (sorry if it is asked already)?

Posted by jordiju  about 1 year ago |  Quote

can we use AMPL to interface with cplex/gurobi as well (sorry if it is asked already)?

I assume you are referring to this. In combination with CPLEX (or Gurobi) this should be fine, yes. I assume you use AMPL to produce the LP-file that is then solved by CPLEX. It would be helpful if you could produce these LP-file separately, if asked to do so, because we don’t use AMPL.

Posted by hur  about 1 year ago |  Quote

@jordiju yes I am referring to that. We use AMPL mainly because it offers an easy way (arguably) to write mathematical programming problems. Its presolve might or might not help with the solution but generally LP relaxation is solved by cplex/gurobi. If you don’t have an AMPL license, we can produce the file that AMPL passes to the solver (with .nl extension) and you should be able to run it using the solver standalone. Does this work for you?

Posted by jordiju  about 1 year ago |  Quote

@jordiju yes I am referring to that. We use AMPL mainly because it offers an easy way (arguably) to write mathematical programming problems. Its presolve might or might not help with the solution but generally LP relaxation is solved by cplex/gurobi. If you don’t have an AMPL license, we can produce the file that AMPL passes to the solver (with .nl extension) and you should be able to run it using the solver standalone. Does this work for you?

Works. Please make sure to count the time for the AMPL modelling and presolve into the 15min timeout.

1