Search found 20 matches

by wutuhan
5 months ago
Forum: Syntax
Topic: Can GAMS do matrix calculations?
Replies: 1
Views: 287

Can GAMS do matrix calculations?

Can GAMS do matrix calculations such the inverse matrix of a matrix? If it can, how to do? If it can't, how should I do?
by wutuhan
9 months ago
Forum: Solvers
Topic: BARON may not give global optimum although the model status is "1 Optimal"
Replies: 1
Views: 899

BARON may not give global optimum although the model status is "1 Optimal"

It seems that BARON may not give global optimum although the model status is "1 Optimal". Is it? When I solve my MINLP model with BARON (to maximize), it gives an OBJECTIVE VALUE 85461884.9974 and the MODEL STATUS is 1 Optimal . But, if I fix some of the 0-1 variables at the values BARON gives and s...
by wutuhan
9 months ago
Forum: Solvers
Topic: Can BARON handle models including nonlinear constraint like x*y>z?
Replies: 0
Views: 259

Can BARON handle models including nonlinear constraint like x*y>z?

Can BARON handle models including nonlinear constraint like x*y>z, where x, y, and z are variables?
by wutuhan
9 months ago
Forum: Syntax
Topic: How to use the result of one model as the initial value of another model?
Replies: 2
Views: 279

How to use the result of one model as the initial value of another model?

How can I use the result of one model as the initial value of another model conveniently? Must I copy and paste the values one by one?
by wutuhan
9 months ago
Forum: Solvers
Topic: Whether a “8 Integer Solution” given by DICOPT is an optimal solution?
Replies: 1
Views: 293

Whether a “8 Integer Solution” given by DICOPT is an optimal solution?

I use DICOPT to solve an MINLP model and it gives model status 8 Integer Solution . Then, how can I know whether it is an globel optimal solution? In the log file, I reads ** Optimal solution. Reduced gradient less than tolerance. and --- DICOPT: Best integer solution found: 567403973.551187 , then ...
by wutuhan
9 months ago
Forum: Solvers
Topic: How to set the GAMS option optCR if I don't know whether the problem satisfies strong duality?
Replies: 2
Views: 456

Re: How to set the GAMS option optCR if I don't know whether the problem satisfies strong duality?

According to your answer, that is to say, for any MINLP, BARON can give its globle optimal solution with the GAMS option "option optCR=0;" as long as it has one, if computing resources are enough. Is it?

Thanks.
by wutuhan
9 months ago
Forum: Solvers
Topic: Can GAMS run two models at the same time?
Replies: 2
Views: 410

Re: Can GAMS run two models at the same time?

Thank you, dirkse. If I run two separate GAMS jobs, then how do they allocate computing resources?
by wutuhan
9 months ago
Forum: Solvers
Topic: Why do DICOPT and BARON come to contradictory conclusions?
Replies: 9
Views: 806

Re: Why do DICOPT and BARON come to contradictory conclusions?

Thank you a lot. I know a MILP formulation can be written for PSP-2 and here I just want to describe the problem. In fact, I know that this problem can be avoided, but I just want to know the reason, although it seems that it is not so important.
by wutuhan
9 months ago
Forum: Solvers
Topic: How to set the GAMS option optCR if I don't know whether the problem satisfies strong duality?
Replies: 2
Views: 456

How to set the GAMS option optCR if I don't know whether the problem satisfies strong duality?

As we know, we say a problem satisfies the strong duality, when its optimal duality gap equals 0. Then, when we don't know whether a problem satisfies the strong duality, if we set the GAMS option optCR to 0, the solving process may never stop and we can never obtain an optimal solution. So, how can...