Dear experts in GAMS,
I have a problem that is similar to cycling scheduling problem in multiple time period.
The objective function is to minimize the total cost over all time period.
Decision is made on each time period and it is a mixed integer nonlinear problem.
The utility function in the period t+1 is dependent on the utility function in the period t, if the decision variable of one object at time t is 1, then the utility function is reset.
to solve this problem, i need to use if-then-else statement in the constraints (or say equations in GAMS terminology).
-
Do you know any good example that also have interdependent equations of multiple period planning?
-
How to code in equation of GAMS the if-then-else statement? what I mean is something like
A(i,j)…1 if t=1 and 2 if t>1;
thanks,
Nam
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Hello,
I can not helo you the first question as I am not familiar with the subject.
Also I noticed that even though the A (parameter I suppose) is defined over i and j, there is a t index…(there is something missing)
Anyway, the second (modeling question) is easily implemented with the following (I changed t with j):
A(i,j)(ORD(j) EQ 1)=E=1;
A(i,j)(ORD(j) GT 1)=E=2;
I hope my comment helps.
Konstantinos
Τη ΠαÏασκευή, 22 ÎοεμβÏίου 2013 4:18:02 μ.μ. UTC+2, ο χÏήστης Nam LeThanh ÎγÏαψε:
Dear experts in GAMS,
I have a problem that is similar to cycling scheduling problem in multiple time period.
The objective function is to minimize the total cost over all time period.
Decision is made on each time period and it is a mixed integer nonlinear problem.
The utility function in the period t+1 is dependent on the utility function in the period t, if the decision variable of one object at time t is 1, then the utility function is reset.
to solve this problem, i need to use if-then-else statement in the constraints (or say equations in GAMS terminology).
-
Do you know any good example that also have interdependent equations of multiple period planning?
-
How to code in equation of GAMS the if-then-else statement? what I mean is something like
A(i,j)…1 if t=1 and 2 if t>1;
thanks,
Nam
\
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Dear Nam
Have you figure out you question no.2? I got the same question. If you know the answers, would you please share with me?
Many thanks,
Qiaomin
On Saturday, November 23, 2013 3:18:02 AM UTC+13, Nam LeThanh wrote:
Dear experts in GAMS,
I have a problem that is similar to cycling scheduling problem in multiple time period.
The objective function is to minimize the total cost over all time period.
Decision is made on each time period and it is a mixed integer nonlinear problem.
The utility function in the period t+1 is dependent on the utility function in the period t, if the decision variable of one object at time t is 1, then the utility function is reset.
to solve this problem, i need to use if-then-else statement in the constraints (or say equations in GAMS terminology).
-
Do you know any good example that also have interdependent equations of multiple period planning?
-
How to code in equation of GAMS the if-then-else statement? what I mean is something like
A(i,j)…1 if t=1 and 2 if t>1;
thanks,
Nam
\
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