Search found 1033 matches

by bussieck
8 months ago
Forum: Syntax
Topic: Table Error 225
Replies: 1
Views: 4814

Re: Table Error 225

I guess some mix with TAB and spaces to get the table aligned. I would remove TABs whereever possible and go with spaces only. If that's not the case you should upload (not copy paste because too much can change) the model file so one can reproduce.

-Michael
by bussieck
9 months ago
Forum: Syntax
Topic: dimension error
Replies: 5
Views: 5717

Re: dimension error

GAMS has domain checking for a good reason. If you circumvent this by declaring your equations without a domain, then the system can't help you with your own mistakes. Your equation res_dem is defined over (s,t) but you access this (to assign to price) as res_dem.M(t,s). If you would have declared w...
by bussieck
9 months ago
Forum: Solvers
Topic: Saving Time of when best solution was found & log and lst files with unique names
Replies: 3
Views: 5257

Re: Saving Time of when best solution was found & log and lst files with unique names

I don't think there is a general "time saving" option in BARON. Even though your best incumbent is found quickly BARON still needs to move the dual bound to reach the optimality tolerance. That can sometimes take a long time, even if you already know and hold the optimal solution. If you c...
by bussieck
9 months ago
Forum: Solvers
Topic: BARON numLoc & local search preprocessing
Replies: 2
Views: 4862

Re: BARON numLoc & local search preprocessing

In GAMS, solver option are passed via a solver option file. You can create this inside a GAMS model via $on/offEcho > baron.opt (at compile time) or via put files at execution time. The use of solver option files is explained here: https://www.gams.com/latest/docs/UG_SolverUsage.html#BASIC_USAGE_SOL...
by bussieck
9 months ago
Forum: Solvers
Topic: BARON: terminates solver when solution does not improve after x amount of time
Replies: 1
Views: 4645

Re: BARON: terminates solver when solution does not improve after x amount of time

Not with BARON. Some solvers allow you "user defined" termination via callbacks and this is made available to GAMS users, see e.g. https://www.gams.com/latest/docs/S_CPLE ... ipstopexpr.

-Michael
by bussieck
9 months ago
Forum: Modeling
Topic: Problem infeasible or unbounded
Replies: 1
Views: 2630

Re: Problem infeasible or unbounded

Nothing. You should use code boxes for your model and output though. You model in unbounded. Just limit the objective variable (e.g. z.lo = -1e6;) and see what "run away" variables you get. Check your application why this should not happen, turn your insight into constraints/model logic. -...
by bussieck
9 months ago
Forum: Syntax
Topic: dimension error
Replies: 5
Views: 5717

Re: dimension error

The attached program succeeds without a problem. If I remove the $stop and let GAMS continue, I get compilation errors when compiling "startup(s*,i,t)", you probably means "startup(s,t,*,i)" at least that makes sense from the code you have later. Now after fixing all this, I get ...
by bussieck
9 months ago
Forum: Syntax
Topic: dimension error
Replies: 5
Views: 5717

Re: dimension error

Don't just paste your GAMS source as normal text. There are fine code boxes in the forum editor. Also this issue is related to data so upload your Excel and GDX file as well so one can reproduce the error.

-Michael
by bussieck
9 months ago
Forum: Modeling
Topic: How do I formulate logical expressions in equations with variables??
Replies: 4
Views: 2506

Re: How do I formulate logical expressions in equations with variables??

Look for logic equations in the forum. It is a frequently asked questions.

-Michael