Search found 13 matches

by mbh
2 months ago
Forum: Modeling
Topic: loop and repeated static calculations
Replies: 1
Views: 313

loop and repeated static calculations

Hi all, I have some parameters that I want to loop over them. I realize that this a repeated static type of calculation. my code looks like this: set kk /kk1*kk10/, jj /jj1*jj1/, d /d0*d4/; parameters bd1(d), bd2(d), id, bd(d), th1, th2, gm, stv ,maxphi, ci(jj), saveth1, saveth2, cill ; th1 = 12; th...
by mbh
2 months ago
Forum: Modeling
Topic: piecewise linearization
Replies: 2
Views: 489

Re: piecewise linearization

Thank you.
by mbh
2 months ago
Forum: Modeling
Topic: piecewise linearization
Replies: 2
Views: 489

piecewise linearization

Hi All, I need to do a piecewise linearization on a function of a multidimensional variable such as: x(n,i,g,f,t,w)**2. My question is that the lambdas or weights that I use should also be multidimensional and have the same dimensions as my variable? I mean should the wights be something like this: ...
by mbh
9 months ago
Forum: Modeling
Topic: linearization of a logarithmic function (log) defined over a variable
Replies: 1
Views: 648

linearization of a logarithmic function (log) defined over a variable

Hi all,
I there anyway to linearize a logarithmic function (log) defined over a variable in GAMS?

Thank you for your help.
by mbh
1 year ago
Forum: Modeling
Topic: "Couenne finished. No feasible point found."
Replies: 0
Views: 809

"Couenne finished. No feasible point found."

Hi all, I am trying to run an MINLP model with Couenne . But I keep getting this message that "Couenne finished. No feasible point found." Model solve summary also reports RESOURCE INTERUPT and 14 NO SOULTION FOUND. However, I am able to find some locally optimum solution using Dicopt. Does it mean ...
by mbh
1 year ago
Forum: Modeling
Topic: Problem with loop in MINLP model.
Replies: 1
Views: 579

Problem with loop in MINLP model.

Hi all, I have a MINLP model which I try to do sensitivity analysis in a loop. I set the starting point into the loop. Now I have a problem that the results that I get using the loop are different from the results of corresponding scenario but without a loop. For example, some times the model with t...
by mbh
1 year ago
Forum: Modeling
Topic: How to use loop to run model several times when some random data is being imported from excel.
Replies: 2
Views: 659

How to use loop to run model several times when some random data is being imported from excel.

Hi All, I import some random data from excel into GAMS. So every time that I run the model the results change because the random numbers change. I'd like to use a loop to rum the model several times by that loop rather than running manually. I would appreciate it if anyone can help me. Sorry if the ...
by mbh
1 year ago
Forum: Syntax
Topic: logical equations & binary variables
Replies: 18
Views: 4834

Re: logical equations & binary variables

Hi again Manassaldi, I have a new question for you and will really appreciate it if you can help me as before. I am still struggling with these kind of logical conditions on endogenous variable in my model. The problem is that p(n) includes a binary variable itself. I mean p(n) = sum(g, t(g) * c(g,n...
by mbh
1 year ago
Forum: Solvers
Topic: Couenne solver error: " Equation 47 is general nonlinear: function vcPower results in a nonlinear expression"
Replies: 1
Views: 637

Couenne solver error: " Equation 47 is general nonlinear: function vcPower results in a nonlinear expression"

Hi all, I have a MINLP model and am using Couenne solver. The solver gives me some errors. The error message are: " Equation 47 is general nonlinear: function vcPower results in a nonlinear expression". From this error message I have no clue what is the reason of the problem. Can anyone help me on t...