Search found 6 matches

by saghafiiii
5 years ago
Forum: Modeling
Topic: Newbie with GAMS
Replies: 3
Views: 3052

Re: Newbie with GAMS

Hi again,

I think infeasibility comes from the constraints below:

Code: Select all

r5.up   = 2.40;
r5.lo   =0;
if you comment these two constraints there is no infeasibility.
I do not know exactly but r5 make the objective function badly constrained.
by saghafiiii
5 years ago
Forum: Modeling
Topic: How to ranging variables
Replies: 7
Views: 5723

Re: How to ranging variables

Hi again. Now I know what is your problem. I'm afraid you can not use ".lo" or ".up" for doing this but I think there is an alternative solution: foe example suppose you have an equation on X in your problem. X + Y * Z >= 6 ; firstly you define : positive variable X , Y , Z; Equa...
by saghafiiii
5 years ago
Forum: Modeling
Topic: Newbie with GAMS
Replies: 3
Views: 3052

Re: Newbie with GAMS

Hi

I'm afraid that some of your equations have been entered wrongly!
for example look at constraint 40!
Am I right?
by saghafiiii
5 years ago
Forum: Modeling
Topic: How to ranging variables
Replies: 7
Views: 5723

Re: How to ranging variables

Hi

I'm afraid you did not explain your problem well.
would you mind making it more clear?
by saghafiiii
5 years ago
Forum: Modeling
Topic: GAMS modeling of an conditional equation
Replies: 2
Views: 4045

Re: GAMS modeling of an conditional equation

Thanks a million. Hi, You have two strict inequalities there: one comparing parameters, the other comparing variables. The parameters can be compared this way, but not the variables. So you could do something like: set i / blah /; alias (i,j); parameter a(i); variables x(i); equation f(i,j); f(i,j)$...
by saghafiiii
5 years ago
Forum: Modeling
Topic: GAMS modeling of an conditional equation
Replies: 2
Views: 4045

GAMS modeling of an conditional equation

Hi everyone. I want to model the equation below in GAMS: equation1.. if( x(i) > x(j), y(i) > y(j); ); it means if x(i) > x(j), then y(i) should be greater than y(j). here y(i) is a variable and x(i) is a parameter. I would be appreciated if someone can help how to model it in GAMS.