Search found 41 matches

by Jubeyer
1 year ago
Forum: Syntax
Topic: How to explicitly mention equations of .inc file in the model description
Replies: 1
Views: 2145

How to explicitly mention equations of .inc file in the model description

Hi, I have been using the 'pwlfunc.inc' for my work. However, I have hundreds of equations among which I want to exclude some and include some at times. When I was looking at the example where the 'pwlfunc.inc' was used: https://www.gams.com/latest/gamslib_ml/libhtml/gamslib_bidpwl.html I have notic...
by Jubeyer
1 year ago
Forum: Modeling
Topic: Difficulty in understanding the sample code on Bid Evaluation
Replies: 2
Views: 1119

Re: Difficulty in understanding the sample code on Bid Evaluation

Hi, Thanks a lot for your reply. I think that I have understood it to some extent. But I do have one additional question. If I want to consider the demand varying with the time so does the quantity and cost will be dependent on time. So, the 'req' will turn into 'req(t)' and so do the 'x(v) and y(v)...
by Jubeyer
1 year ago
Forum: Modeling
Topic: Difficulty in understanding the sample code on Bid Evaluation
Replies: 2
Views: 1119

Difficulty in understanding the sample code on Bid Evaluation

Hi, I have been trying to understand the code for bid evaluation in :https://www.gams.com/latest/gamslib_ml/libhtml/gamslib_bidpwl.html As per my understanding goes the x(v) is a variable that represents the quantity each vendor bids for whereas in equation defy(v) the corresponding cost has been ca...
by Jubeyer
1 year ago
Forum: Syntax
Topic: Running problem with the piecewise linear example code in the GAMS portal
Replies: 2
Views: 1647

Re: Running problem with the piecewise linear example code in the GAMS portal

Hi, I have figured out the cause perhaps. The pwlfunc.inc file was not found while executing the code, however when I changed to the .inc filename with its address then it works. Perhaps GAMS was not added to my environment variable path. Anyway, thanks a lot. At the beginning I thought that the pwl...
by Jubeyer
1 year ago
Forum: Syntax
Topic: Running problem with the piecewise linear example code in the GAMS portal
Replies: 2
Views: 1647

Running problem with the piecewise linear example code in the GAMS portal

Hi, I have been trying to execute the code given at :https://www.gams.com/latest/gamslib_ml/libhtml/gamslib_bidpwl.html But I am getting this error message: image.png I have these lines in my pwlfunc.inc file: BidPwl s x y l g v loop(BidPwl_Seg(v,s)$(ord(s) > 2), BidPwl(v,s,'y') = BidPwl(v,s-1,'y') ...
by Jubeyer
1 year ago
Forum: Solvers
Topic: Parallel Mode and Number of Threads Setting in cplex.opt file
Replies: 3
Views: 2971

Re: Parallel Mode and Number of Threads Setting in cplex.opt file

Yes, I did.

I have done the following in my .gms file.
MyModel.iterlim =500000;
MyModel.optcr = 0.001;
MyModel.reslim = 1800;
option solvelink=5;
MyModel.optfile = 1;
heaplimit = 30000;

And I have tried to specify the thread number there as well like the following:
MyModel.threads=0;
by Jubeyer
1 year ago
Forum: Solvers
Topic: Parallel Mode and Number of Threads Setting in cplex.opt file
Replies: 3
Views: 2971

Parallel Mode and Number of Threads Setting in cplex.opt file

Hi,
I have set,

threads=0
and
parallelmode=-1

in the cplex.opt file ; but while executing the logfile is not showing up those values. Can anyone tell me how to define them correctly?

Best Regards.
by Jubeyer
1 year ago
Forum: Modeling
Topic: How to hold a constant variable value consecutively?
Replies: 1
Views: 1158

How to hold a constant variable value consecutively?

I have been trying to model a constraint for a variable in an MIP formulation. My problem is like this; X(t) is a variable, whose value has to remain constant for some pre-defined consecutive periods after its value decreases. So, say at t=2, the X(t=2) value decreases from X(t=1), then X(t) should ...
by Jubeyer
1 year ago
Forum: Modeling
Topic: Approach for handling non-linear equations
Replies: 1
Views: 1950

Approach for handling non-linear equations

Hi, One of my constraints involves formulating this relationship between two variables x and y as shown in this picture: image.png Since this is a non-linear relationship, it becomes difficult to solve the problem. From my past experience, it is really difficult to get a solution for a non-linear pr...
by Jubeyer
2 years ago
Forum: Syntax
Topic: Command line Keyword in the gams script
Replies: 4
Views: 4608

Command line Keyword in the gams script

Hi, What is the correct syntax of including the command line keyword in the code? For example, I am executing this command >gams mycode keep=1 --USE_GAMS='YES' So, how should I write the 'keep=1 --USE_GAMS='YES' ' in the syntax of the .gms file instead of writing each time in the command line. My ot...