GAMS World Forum

Thanks for your solution. I'm really appreciate it.

Hi, My variable is the number of plant (i.e. 3.2 plants) and I would like to round it up to the next integer (i.e. 4 plants). This is to calculate the capital cost (number of plant x capital cost per plant) as we cannot build 3.2 plants. At the same time, this variable need to keep as decimal point ...

No synchronization is needed among the variables. Could you provide an example code for the method you mentioned?

Many thanks,
Jun Keat

Hi,

I'm trying to minimize three objective function simultaneously (cost, human health and environmental impact) for waste management system. What method can I use to do the optimization? I have tried the eps constraint method but it didn't give me the solutions, Jun keat

Yes, as the program stops halfway where my last screenshot shows so I cannot get the logfile.

Hi Fred,

This is the result I obtained. Seems like the code just stop after getting one solution. Is there some problem with my laptop or my software?

Jun Keat

Hi Fred,

I'm only can obtain one result in gdx. file. I guess it suppose to have a set of pareto optimal solutions?

Jun Keat

Hi,

I'm using epsilon constraint method to solve three objective functions. The code runs fine but it stops randomly halfway through execution. I am wondering where is the problem. Jun Keat

Hi Michael, Thanks for the reply. The model is really infeasible. However, I don't know how to make it feasible. Can you help me to check on my code? Thanks so much! Sets i 'waste type' / waste-1 * waste-5 / j 'power plant' / plant-1 * plant-7 / ; Parameters w(i) 'waste amount(mil)' / waste-1 40 was...

Hi, How come I still get negative value even though I have set the variable to be positive variable? It still give me negative answer even if I have set a demand constraint, meaning that each plant can not receive a negative demand for any circumstances. Is there any other methods to avoid negative ...