Search found 27 matches

by Alexanre.ito
6 days ago
Forum: Modeling
Topic: 2 models using the variable of the first as the set of the second
Replies: 6
Views: 364

Re: 2 models using the variable of the first as the set of the second

Hi Renger, It it possible to do this same idea, using all the equation at the same model? Hi qr is a variable, so one should use qr.L in the parameter and you should stage it like this (don't repeat the line with the definition of the parameter). If you still have a division by zero, this can be cau...
by Alexanre.ito
1 week ago
Forum: Modeling
Topic: 2 models using the variable of the first as the set of the second
Replies: 6
Views: 364

Re: 2 models using the variable of the first as the set of the second

Thank you very much Renger,
it helped me a lot.
it still hasn't solved my problem, but for what I'm trying to do, it worked really well.
by Alexanre.ito
1 week ago
Forum: Modeling
Topic: 2 models using the variable of the first as the set of the second
Replies: 6
Views: 364

Re: 2 models using the variable of the first as the set of the second

Thank you very much Roger, this is exactly what I wanted. But I think my code is not considering my variable as a SET. For when I insert an error is presented: 472 flag (n, np) $ (qr (n, np)> 0) = 1; **** $143 Did you know how to put this variable as a SET together with the value? so that I can cons...
by Alexanre.ito
1 week ago
Forum: Modeling
Topic: 2 models using the variable of the first as the set of the second
Replies: 6
Views: 364

2 models using the variable of the first as the set of the second

Hi, I'm with a problem that I have a problem with 2 models. The first is ok, my model optimize the flow at the tubes. At the second I need to use equations, using that flow, but the tubes with no flow (zero), it shod be exclude. But I don't know how to express this condition. My model is showing thi...
by Alexanre.ito
2 months ago
Forum: Syntax
Topic: Binary variables
Replies: 2
Views: 415

Re: Binary variables

Yes, thanks. Hi, you should always check the model and solver status. S O L V E S U M M A R Y MODEL Rede OBJECTIVE cost TYPE MINLP DIRECTION MINIMIZE SOLVER SBB FROM LINE 122 **** SOLVER STATUS 4 Terminated By Solver **** MODEL STATUS 9 Intermediate Non-Integer **** OBJECTIVE VALUE 7.0711 Intermedia...
by Alexanre.ito
2 months ago
Forum: Syntax
Topic: Binary variables
Replies: 2
Views: 415

Binary variables

Hi I have no more ideas to correct my model.
I don't know why my binary variables is not a binary.
The binary result is not a binary, even declaring that as "Binary Variable"

could some one help me with this?
by Alexanre.ito
2 months ago
Forum: Syntax
Topic: SET or PARAMETER
Replies: 2
Views: 450

Re: SET or PARAMETER

I found a solution, I tried to insert into my code but it not worked, a error is indicated as 250 in the manual have the possibility to work with "Many-to-Many Mapping" I insert the same exemplo of the manual and the error was the same. but I'm using GAMS 22.5, could It (Many-to-Many Mapping) not wo...
by Alexanre.ito
2 months ago
Forum: Syntax
Topic: SET or PARAMETER
Replies: 2
Views: 450

SET or PARAMETER

Hi I with a problem that I don't know how to declare, if is a SET or a PARAMETER. I want that conditions result in a relation of the possibilities (t) with the arcs (nn). Set n nodes / n1 * n3 / nn(n,n) tub t connection type / t1 * t4 / p(n,n,t) connection possibilities of stretches I'd like a relat...
by Alexanre.ito
4 months ago
Forum: Modeling
Topic: Jacobian elements in the row are very small
Replies: 2
Views: 999

Re: Jacobian elements in the row are very small

Thanks for your time, and I'm sorry if I was not so clear, Your assumptions is right. Changed the situation but still not working. " ir1 are variables. Do they have any bounds on them? " Yes, here it is: they are too small so I tried the scalar function, explained at the end. Scalars imin slope Min ...
by Alexanre.ito
4 months ago
Forum: Modeling
Topic: Jacobian elements in the row are very small
Replies: 2
Views: 999

Jacobian elements in the row are very small

Hi, I'm using the SBB solver as MINLP. in my model have some equations that the variables are very small, between [0.001 , 0.1]. So I use ".scale". But some equations still have this problem. Some equations have power lower than 1 (ex. var**0.47), so I change the equation to ( var1 **100 =e= ....var...