## Search found 66 matches

1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Hi Manassaldi, i tried to execute the BigM-Relaxation approach of my model. However my computer was out of memory. The workspace was more than 27.000 Mb and then GAMS stopped with the message "Out of memory". I think by memory GAMS is referring to RAM and not to harddrive. Because on my harddrive th...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Hi Manassaldi, So, if this upper bound is equal to 50 you have to insert 50 equation for x and 50 for y. I don't really have an upper bound. The only upper bound I have is the number of timeslots,which is 1440. So I have to insert 1440 *2= 2880 equations when using the first approximation? What abou...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Hi Manassaldi, Thank you for your answers I still have questions: 1) In your first formulation I think you have to insert equations for all timeslots and the number of time in which x is has to be know in advance. Is that correct? eqfirstx(t).. 1 - x(t) + sum(tp\$(ord(tp) lt ord(t)),x(tp)) + xfirst(t...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Thanks Manassaldi for your answer, but I do nor understand your code: set t /1*1440/ ; alias(t,tp,tpp); binary variable x(t) y(t) ; variable z ; equation eq1,eq2,eq3,eq4,eq5,eq6,eqobj ; eq1(t,tp).. sum(tpp\$(ord(tpp) le ord(t)),x(tpp)) =l= ord(tp) + (1-xpos(tp,t))*1440; eq2(t,tp).. sum(tpp\$(ord(tpp) ...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Thanks Manassaldi for your answer (and your general great effort :) ), I have to admit that I do not really understand the things you said. What is meant by: I think you must to propose the maximum time in which x(t) = 1 and y(t) =1 before, but you have to modifies some restriction. As I said in the...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Thanks once again Manassaldi for your good answer, Now I understood how your concept works. You said that I'll have to do this for every occurence of x(t)=1 and y(t)=1 I have to comments/questions regarding this: 1) The number of timeslots, inwhich x(t) = 1and y(t) =1 is not known in advance and has...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Re: Maximizing the difference in the order of binary variables

Hi Manassaldi, thank you for your answer. Unfortunately I'm having a hard time understading what you posted. Even the first equation is not understandable for me (I have not tried to understand the other equations yet, because I am struggeling even with the first one): eqfirstx(t).. 1 - x(t) + sum(t...
1 year ago
Forum: Modeling
Topic: Maximizing the difference in the order of binary variables
Replies: 28
Views: 3907

### Maximizing the difference in the order of binary variables

Hi guys, the problem I am facing is going to be difficult to explain and I strongly question whether something like this is solvable with GAMS. But I'll try: Lets say we have two binary decision variables x(t) and y(t) and lets assume they have the following values: t: 0 1 2 3 4 x: 0 0 1 0 1 y: 1 0 ...
1 year ago
Forum: Modeling
Topic: Ensuring realations between decision variables
Replies: 6
Views: 1395

### Re: Ensuring realations between decision variables

Hi Manassaldi,

it seems to work How did you derive those equations? Also with the basic steps?

Thanks a lot for your great help!
1 year ago
Forum: Modeling
Topic: Modeling the absolute value
Replies: 21
Views: 5102

### Re: Modeling the absolute value

Thanks again for the answers. Where can I read more about those basic steps? I typed it into google but somehow I could not find useful information about them.