Search found 54 matches

by GabrielYin
9 months ago
Forum: Solvers
Topic: MOSEK Licensing in GAMS
Replies: 0
Views: 613

MOSEK Licensing in GAMS

Hi all, I recently need to use MOSEK to solve large-scale SOCP problems, but I really do not know how to add a MOSEK license to my GAMS system. I used to add a GAMS license to my GAMS system by just copying to the clipboard and paste in the Help button in the GAMS IDE, which includes CPLEX. I have a...
by GabrielYin
11 months ago
Forum: Syntax
Topic: Different CPLEX threads influences final results?
Replies: 4
Views: 1603

Re: Different CPLEX threads influences final results?

No, the threads selection may have an impact on your results. If you have different optimal solutions (or have positive optimality tolerances) you will have a different path through the algorithm if you change something (threads, OS, different bit-ness of the software (32/64bit), ...). Only if you ...
by GabrielYin
11 months ago
Forum: Syntax
Topic: Different CPLEX threads influences final results?
Replies: 4
Views: 1603

Re: Different CPLEX threads influences final results?

Sorry, for threads = 4 case, the elapsed time is 5min38sec.

Gabriel
by GabrielYin
11 months ago
Forum: Syntax
Topic: Different CPLEX threads influences final results?
Replies: 4
Views: 1603

Different CPLEX threads influences final results?

Hi all, I have tried to set different threads for CPLEX solver to facilitate my computation, but weirdly, different threads gave different final results. Based on my knowledge, setting threads will only influence the speed because it is for parallel computing, but will not have any impact on the exe...
by GabrielYin
1 year ago
Forum: Tools
Topic: How to fancily label and observe .lst file
Replies: 0
Views: 1398

How to fancily label and observe .lst file

Hi all, I am using a linux-version GAMS in a linux system. It does give me a .lst file after compilation, but it cannot be viewed as in GAMS IDE, like shown in the following. .lst file in a GAMS IDE is with very fancy labels and can be easily viewed. https://image.ibb.co/b9damp/lst.jpg I have tried ...
by GabrielYin
1 year ago
Forum: Modeling
Topic: MIQP Problem Formulated as MIQCP?
Replies: 5
Views: 1346

Re: MIQP Problem Formulated as MIQCP?

Gabriel, From the log output you sent I would conclude that the GAMS/CPLEX link has found a general non-linear constraint in your problem. Simply put, it does not think it is a QCP. The specific output I refer to is: General nonlinearity detected in row subobjregu -Steve Thank you! However, the row...
by GabrielYin
1 year ago
Forum: Modeling
Topic: MIQP Problem Formulated as MIQCP?
Replies: 5
Views: 1346

Re: MIQP Problem Formulated as MIQCP?

Hi, Perhaps you have use x**2 to represent your quadratic part. **2 is the real power (https://www.gams.com/latest/docs/UG_Parameters.html#INDEX_power_2d__21_function) and can't be used in QCP models. So better use power(x,2) or even simpler sqr(x) . -Michael Thank you! Actually I was using abs() w...
by GabrielYin
1 year ago
Forum: Syntax
Topic: Continued Equality for Condition
Replies: 3
Views: 1063

Re: Continued Equality for Condition

Thanks for your kind reply! That should be the best solution!

Gabriel
by GabrielYin
1 year ago
Forum: Modeling
Topic: MIQP Problem Formulated as MIQCP?
Replies: 5
Views: 1346

MIQP Problem Formulated as MIQCP?

Hi all, I got one issue reporting "System Failure". My opt. problem has a mixed-integer quadratic objective function with linear constraints, and I defined it as an MIQCP problem. the report summary is as follows. S O L V E S U M M A R Y MODEL dualspregu OBJECTIVE subdualregu TYPE MIQCP DIRECTION MI...
by GabrielYin
1 year ago
Forum: Syntax
Topic: Continued Equality for Condition
Replies: 3
Views: 1063

Re: Continued Equality for Condition

Sorry but I found the solution myself :D And I apologize for the error in the post that I use 'n' twice for index. I share my solution with you. loop(i, ... loop(n, s(n) = a('1') - a(n); ); if(sum(n, s(n)) = 0, k = 1; ); break$(k = 1); continue; ); If you have better idea please share with me too! T...