Search found 502 matches
- 2 days ago
- Forum: Bugs
- Topic: MSNLP solver "stops" before running the algorithm
- Replies: 3
- Views: 97
My bet is on Ipopt as the culprit. You could use the solver as an executable (add solvelink 2 to the msnlp.opt) and observe what process hangs. Moreover, it makes much more sense to use an active set solver like Conopt within MSNLP. MINLP is about restarts and an interior code (like Ipopt) and resta...
Never heard a request like this before... GAMS does not make noises but you can execute any program with execute. Here is a way to play a wav file (on Windows): ... solve mymodel us lp min z; execute 'powershell -c (New-Object Media.SoundPlayer "C:\Windows\Media\notify.wav").PlaySync();' -Michael
- 1 week ago
- Forum: Syntax
- Topic: Data exchange: $gdxin works but execute_load fails
- Replies: 1
- Views: 124
Understand the difference between compile time and execution time (https://www.gams.com/32/docs/UG_GamsCall.html#UG_GamsCall_TwoPass). GAMS cannot extend the universe of labels (set elements) at run time. All labels must be known at the end of compilation. Your program has no labels and hence execut...
Branch and bound methods (as implemented in Baron) work with a relaxation ("Best possible") and an incumbent ("Solution"). If the difference (absolute ("Absolute gap") and relative ("Relative gap")) between the two is 0 then your incumbent is the optimal solution. Since you have the tolerance for th...
You can loop in GAMS. Lets say you want to solve your model over and over again with values for parameter p from 1 to 3 in steps of 0.1, the following code does that: ... set ps / p1*p30 /; parameter objrep(ps); loop(ps, p = 1 + (ord(ps)-1)/10; solve mymodel min z us lp; objrep(ps) = z.l; ); ... -Mi...
From what you sent (an lst file) it is hard to verify the solution reported by SBB. I see no obvious reason why qe(0) should be 69.975. There are multiple ways to verify that a solver reports a solution correctly, e.g. Examiner (https://www.gams.com/latest/docs/S_EXAMINER.html) or just solve a secon...
- 3 weeks ago
- Forum: Contributed Documentation and Tools
- Topic: GAMS-L mailing list
- Replies: 0
- Views: 297
There is an older alternative to this forum and there are still a couple of active users out there (mostly users from the economic modeling community). Here is a bit information about the mailing list: There are two possible ways to subscribe: Use a web interface to join and leave the list and to br...
You need to create an SBB option file (as documented here https://www.gams.com/latest/docs/UG_SolverUsage.html#BASIC_USAGE_SOLVER_OPTION_FILE). You can create this file even from within GAMS in various ways, e.g. $onecho > sbb.opt memnodes 1e6 $offecho mymodel.optfile = 1; option minlp=sbb; solve my...