GAMS World Forum

Hi, I don't know what you mean by this But now, having to write it professionally Almost all GAMS model have multiple indexes, this is as professional as it gets. There are ways to ""flatten" the index space, but that looks very ugly, so before suggesting ways to do this, I would like...

Since you haven't gotten any answer, I suggest to share the model to make this reproducible. -Michael

Rob, Studio adds a couple of parameters to the GAMS command line. Obviously, the last one pf="." is wrong. pf points to a GAMS parameter file with more command line options. Studio recently introduced the "GAMS Parameter File" feature, see https://www.gams.com/latest/docs/T_STUDI...

The steps that takes long is the extraction of the Q matrix from the non-linear instructions. There are basically two algorithms to do this and we default to the one (ThreePass) that is is fast in most cases. You might benefit from using the other algorithm (DoubleForward). We even have a "conc...

Hi GAMS Users, We would like to announce the availability of the GAMS Beta Release 44.0.0. Please consult the beta release notes for details about new features and updated solvers: https://www.gams.com/beta/docs/RN_44.html If you are interested in experimenting with this beta release, please downloa...

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

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...

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...

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...

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