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Problem while modelling Pareto Optimal Solution
Posted: Sun Jan 15, 2023 8:35 am
by Balu6667
Respected Everyone, please check the below-attached code.
This is a multi-objective scheduling technique.
While optimizing the objectives separately, they are working fine, but when I tried to use Pareto optimal, I got constant optimized values instead of getting mutually varying values.
Please provide the error in case anyone finds it in the below attached and posted.
Thank you in advance.
Re: Problem while modelling Pareto Optimal Solution
Posted: Mon Jan 16, 2023 11:10 am
by bussieck
Have you ever looked at the ranges parameter? I get:
Code: Select all
---- 243 PARAMETER ranges
OF1min 625.394, OF2max 35.830, OF2min 35.830, OF1max 625.394
Not much wiggle room. When I try to explicitly min/max the two objectives via:
Code: Select all
solve problem using MINLP minimizing of1; ranges('OF1min') = of1.l;
solve problem using MINLP maximizing of1; ranges('OF1max') = of1.l;
solve problem using MINLP minimizing of2; ranges('OF2min') = of2.l;
solve problem using MINLP maximizing of2; ranges('OF2max') = of2.l;
I get
Code: Select all
---- 250 PARAMETER ranges
OF1min 625.394, OF1max 985.626, OF2min 35.830, OF2max 35.830
So not much room to get differences for OF2 and hence to point in doing multi-objective optimization. It's enough to min OF1.
-Michael
PS I used global MINLP solver BARON.
Re: Problem while modelling Pareto Optimal Solution
Posted: Wed Jan 18, 2023 4:53 pm
by Balu6667
Respected sir,
Thank you for your answer.
As you have mentioned that there is no room for doing two objectives, I tried to make it into a single objective as coded in the below-attached files. but I am getting the error while doing so.
Sir, can you please resolve the issue and provide me with the path to get it for the below-attached codes (in between both the below codes I changed the formula of the previous code file's second objective ).
Thanks in advance.
Re: Problem while modelling Pareto Optimal Solution
Posted: Thu Jan 19, 2023 8:39 am
by bussieck
Sorry, no idea what you are asking for. I download both models. They both compile and solve fine. What do you think is the matter with them?
-Michael
Re: Problem while modelling Pareto Optimal Solution
Posted: Thu Jan 19, 2023 7:46 pm
by Balu6667
respected sir,
while I was trying to optimize, it was showing.
DICOPT: Terminating
DICOPT: stopped on NLP worsening.
Thank you in advance.
Re: Problem while modelling Pareto Optimal Solution
Posted: Fri Jan 20, 2023 3:26 pm
by Balu6667
Respected sir,
For the above-attached codes (Untitled 11 and 12), when I was trying to optimize, it was showing the following errors.
DICOPT: Terminating
DICOPT: stopped on NLP worsening
Thank you in advance. Please provide the solution.