Search found 6 matches

by jgrimm
1 month ago
Forum: Syntax
Topic: Delete files during execution not in compile phase
Replies: 4
Views: 374

Re: Delete files during execution not in compile phase

Hi all, thanks for the hints and sorry for my late response. It works perfectly! Thank you :) Currently I am facing some kind of other question using BCH facility. I am using userincbcall to identify cuts. So what happens (sample log entries): userincbcall executed: incumbent rejected (-> because pr...
by jgrimm
2 months ago
Forum: Syntax
Topic: Delete files during execution not in compile phase
Replies: 4
Views: 374

Delete files during execution not in compile phase

Hi all, I am using the usercutcall und userIncbCall functionality by the BCH facility. The logic is as follows: - userincbcall is called once incumbent solution has been determined during branch and bound (/cut) process. This might happen several times in a sequence (i.e. several incumbents are foun...
by jgrimm
3 months ago
Forum: Syntax
Topic: BCH | Cplex | Branch and Cut
Replies: 6
Views: 766

Re: BCH | Cplex | Branch and Cut

Hi Fred,

perfectly answered. Thank you for your help ! :D

Kind regards,
Jonathan
by jgrimm
4 months ago
Forum: Syntax
Topic: BCH | Cplex | Branch and Cut
Replies: 6
Views: 766

Re: BCH | Cplex | Branch and Cut

Hi Fred, I was able to implement it on my own. I have done two implementations and seems like both are working properly. First implementation is using BCH facility (usercutcall and userincb). Second implementation is looping over branch & bound solution process several times (and adding cuts after s...
by jgrimm
4 months ago
Forum: Syntax
Topic: BCH | Cplex | Branch and Cut
Replies: 6
Views: 766

Re: BCH | Cplex | Branch and Cut

Hi Fred, I have been checking the bchtsp.gms before and took some code samples from it. My rework of the code fragments led to the unresolvable issue. It looks much better now. Thank you! In the meantime I have been working on the code and made some more improvements (and fixes). It is running and g...
by jgrimm
5 months ago
Forum: Syntax
Topic: BCH | Cplex | Branch and Cut
Replies: 6
Views: 766

BCH | Cplex | Branch and Cut

Hi all, currently I am trying to implement an simple branch and cut algorithm using the GAMS Branch & Cut Facility and CPLEX. In a simple implementation a relaxed problem formulation is strengthened in branching process by providing some additional cuts (Problem VRP). A relaxed MIP problem formulati...