Search found 18 matches

by achristensen
1 month ago
Forum: Syntax
Topic: GAMS/CPLEX Model Creation Time
Replies: 3
Views: 870

Re: GAMS/CPLEX Model Creation Time

Hi Gabriel, If you are in a situation where the solve is quick, but everything else is slower... a good place to start is to turn on profile: option profile = 1; You might also want to turn off some of the printing to the LST: option limrow = 0; option limcol = 0; option solprint = off; You will see...
by achristensen
2 years ago
Forum: Syntax
Topic: Unknown identifier entered as set
Replies: 2
Views: 2637

Re: Unknown identifier entered as set

Hi there, It seems like you might need a mapping set that will link the mine to the country it is in... something like this: set mine / mine1*mine3 /; set country / Russia, Germany /; set mine2country(mine,country) / mine1.Russia mine2.Russia mine3.Germany /; Then you could probably do something lik...
by achristensen
2 years ago
Forum: Modeling
Topic: The fastest way to hide many lines
Replies: 2
Views: 1768

Re: The fastest way to hide many lines

In Studio you can highlight the area that you want to comment out and do (on my mac) CMD + Shift + 8 (aka CMD + *). If this doesn't work go to Edit > Advanced > Toggle Comment Line(s).
-adam
by achristensen
3 years ago
Forum: Modeling
Topic: I need help from someone with a paid license
Replies: 3
Views: 2793

Re: I need help from someone with a paid license

There are reasons that licenses exist, but we do try and make it easy for certain groups to obtain access to "community licenses". A community license is (from our website)... "Users can request a free community license from sales@gams.com. The community license lets you generate and ...
by achristensen
4 years ago
Forum: Syntax
Topic: Need help with multiple indices variable definition and indice/set domains within constraints (Vehicle Routing Problem)
Replies: 1
Views: 3646

Re: Need help with multiple indices variable definition and indice/set domains within constraints (Vehicle Routing Probl

Hi gravityman123, There is a lot to unpack in your post (and this won't be a complete answer) but one thing that struck me is that your problem has a network in it, but you have not defined a set that describes the arcs in your network. For all sorts of problems it's a good programming practice to s...
by achristensen
4 years ago
Forum: Modeling
Topic: Error 352
Replies: 5
Views: 4601

Re: Error 352

best if you post some code.... is it possible to share publicly?

--adam
by achristensen
4 years ago
Forum: Modeling
Topic: Error 668 , 37 , 409
Replies: 2
Views: 5413

Re: Error 668 , 37 , 409

just a couple typos...
you have

Code: Select all

$if exists $ include matdata.gms
it should be

Code: Select all

$if exist matdata.gms $include matdata.gms
does that fix everything?

--adam
by achristensen
4 years ago
Forum: Tools
Topic: using invert tool on Ubuntu
Replies: 1
Views: 3042

Re: using invert tool on Ubuntu

if the return code from an external program is anything but zero that means that something went wrong with the execution of the external program. In this case it's because invert.exe is only windows compatible.

best,
adam
by achristensen
4 years ago
Forum: Modeling
Topic: Help with GAMS Error 140
Replies: 1
Views: 2357

Re: Help with GAMS Error 140

an Error 140 is an "unknown symbol". It appears that you have not defined "Pe" or you might have a typo? Should it be "Pec" of "Ped"? BTW... when i run this, I get 25 errors... so you will need to fix more than just the last line. If you have a different numbe...
by achristensen
4 years ago
Forum: Syntax
Topic: How to write this constraint
Replies: 4
Views: 3419

Re: How to write this constraint

you cannot use a loop statement within an equation definition... you need to somehow structure your equation definition so that the looping behavior you are hoping for is taken care of entirely with set operations. This might also necessitate an alias set. While doing this you might also need to ret...