Search found 207 matches

by Fred
1 week ago
Forum: Solvers
Topic: Variable stopping criteria based on run time
Replies: 2
Views: 91

Re: Variable stopping criteria based on run time

Hi, With CPLEX (the log tells me that you use CPLEX) you can update the solver option file. I attached an example based on model dice from the GAMS model library and the trigger file example from the support wiki. Cplex starts with optcr=0.01, after ~10 seconds it uses a cplex.op2 with optcr=0.1 and...
by Fred
1 week ago
Forum: Syntax
Topic: Random Numbers Beta
Replies: 1
Views: 75

Re: Random Numbers Beta

Hi,

GAMS comes with a stochastic library that allows you draw random numbers from the beta distribution: https://www.gams.com/latest/docs/UG_Ext ... ticLibrary

I hope this helps!

Fred
by Fred
4 weeks ago
Forum: Tools
Topic: Load zero values to GAMS from GDX File
Replies: 6
Views: 783

Re: Load zero values to GAMS from GDX File

If I run parameter VD0, VINTCD0, VFACD0, VF0, VINTCF0, VFACF0, TAXM0, VT0, TN, VQH0, QG, QINV, FSAVD0, FSAVF0, FSAVK0, SIGMA, GAMMA, SIGMAP, ITA; $call gdxxrw FRICTION.xlsx @FRICTION.txt $gdxin FRICTION.gdx $load VD0 VINTCD0 VFACD0 VF0 VINTCF0 VFACF0 TAXM0 VT0 TN VQH0 QG QINV FSAVD0 FSAVF0 FSAVK0 SI...
by Fred
1 month ago
Forum: Modeling
Topic: A "division by zero" in a line where no calculation happens
Replies: 7
Views: 1933

Re: A "division by zero" in a line where no calculation happens

Hi,

As I wrote in my previous post, the line numbers refer to the echo print in the lst file.
Looking up the lines and checking the data, there is obviously a division by zero.

Best,
Fred
by Fred
1 month ago
Forum: Modeling
Topic: A "division by zero" in a line where no calculation happens
Replies: 7
Views: 1933

Re: A "division by zero" in a line where no calculation happens

Hi,

Note that the line numbers refer to the echo print in the lst file.
Unfortunately, some if the include files are missing in the zip archive, so it is not possible to reproduce the problem.

Best,
Fred
by Fred
1 month ago
Forum: Modeling
Topic: Variable Start-up cost in the Unit Commitment Problem
Replies: 4
Views: 742

Re: Variable Start-up cost in the Unit Commitment Problem

When you run set i / -2, -1, 0, 1, 2 /; you should get the following error which is very explicit about UNQUOTED elements having to start with a letter or digit. 1 set i / -2, -1, 0, 1, 2 /; **** $338$338 $172$172 **** 172 Element is redefined **** 338 Unique element expected - symbol was not an ele...
by Fred
1 month ago
Forum: Archive Google Group
Topic: GAMS Studio dark mode
Replies: 2
Views: 979

Re: GAMS Studio dark mode

Yes, see https://www.gams.com/latest/docs/T_STUD ... O_SETTINGS

For Windows the dark theme was introduced in Studio version 0.14.6.
If you download the latest GAMS from https://www.gams.com/download/ you get Studio version 1.1.0 and should be good.

I hope this helps!

Fred
by Fred
1 month ago
Forum: Tools
Topic: International characters
Replies: 1
Views: 566

Re: International characters

Hi, I guess that you are executing GAMS in a directory with non-ASCII characters. GAMS has trouble with this. Please run GAMS in a directory that does only contain [a-zA-Z] characters. If this is not possible (because your home directory already has non-ASCII characters in it) choose a solveLink opt...
by Fred
2 months ago
Forum: Modeling
Topic: Warehouse Problem with minimizing the net present value of the cost
Replies: 2
Views: 270

Re: Warehouse Problem with minimizing the net present value of the cost

Hi, Problem is how you use set t at the end of equation cost.. TC =e= sum[t, [{SP(t)*(buy(t)-sell(t))+SC*stock(t)}/((1+i)**t)]]; While you use set elements 1,2,3,4, set elements can in general be strings (e.g. apple, orange, cherry, ...) which is why you cannot make calculations with set elements li...
by Fred
4 months ago
Forum: Syntax
Topic: Run a program
Replies: 4
Views: 465

Re: Run a program

What I suggested was a way to get your own license, free of charge, that allows you to solve the model yourself. The license type is called a community license (https://www.gams.com/latest/docs/UG_License.html#GAMS_Community_Licenses). I thought that you would probably prefer being able to solve you...