Hi Michael,
You are absolutely a star! I actually need the maximum travel distance for the model as well and your answers are really helpful. Thank you a million and hope you have a wonderful week.
Best regards,
Lina
Search found 11 matches
- 5 years ago
- Forum: Syntax
- Topic: variable ensuring two index are different
- Replies: 2
- Views: 7157
- 5 years ago
- Forum: Syntax
- Topic: variable ensuring two index are different
- Replies: 2
- Views: 7157
variable ensuring two index are different
Hi Guys, I am trying to develop a model with one of the decision variable being the following: W(i,j): store i is the closest alternative store for region j; i assume that each customer region has a local store and want to study the customer shopping behavior when their local store is closed - e.g. ...
- 5 years ago
- Forum: Modeling
- Topic: The shortest Route problem
- Replies: 1
- Views: 2751
The shortest Route problem
Hi everyone, As I am new to GAMS and really want to get my head around it for modelling, I tried to compile the examples in the GAMS Studio library myself. I could not really understand the x(i,ip,ipp) in the example given, as I thought the decision variable should be a binary to see whether a certa...
- 5 years ago
- Forum: Solvers
- Topic: Solver didn't provide marginals for model fulfilment
- Replies: 6
- Views: 7593
Re: Solver didn't provide marginals for model fulfilment
Dear Steve,
Thank you very much indeed for the illustration and explanation! I shall try with the optimality tolerance reduction and see how it goes. Have a good week!
Cheers,
Lina
Thank you very much indeed for the illustration and explanation! I shall try with the optimality tolerance reduction and see how it goes. Have a good week!
Cheers,
Lina
- 5 years ago
- Forum: Solvers
- Topic: Solver didn't provide marginals for model fulfilment
- Replies: 6
- Views: 7593
Re: Solver didn't provide marginals for model fulfilment
Hi dirkse,
Thank you so much for the reply. I got a screenshot for the log. I have reduced the the number of stores from 8 to 3 to hopefully understand the mechanism better.
Thank you so much for the reply. I got a screenshot for the log. I have reduced the the number of stores from 8 to 3 to hopefully understand the mechanism better.
- 5 years ago
- Forum: Solvers
- Topic: Solver didn't provide marginals for model fulfilment
- Replies: 6
- Views: 7593
Re: Solver didn't provide marginals for model fulfilment
Hi Steve, Thank you for pointing that out for me! I totally forgot to complete my profile. Basically, I have developed a MINLP model for online order fulfilment for my study. I wanted to check the marginal value to see the shadow price for sensitivity analysis. I used ANTIGONE and it gives marginal ...
- 5 years ago
- Forum: Solvers
- Topic: Solver didn't provide marginals for model fulfilment
- Replies: 6
- Views: 7593
Solver didn't provide marginals for model fulfilment
Hi everyone, I used BARON for my MINLP model (linear constraint but non linear objective function) and the solver report shows normal completion and solver did not provide marginals for model fulfilment. Does it mean the solution is not optimal? If so, how should I solve the problem? Thank you very ...
- 5 years ago
- Forum: Modeling
- Topic: How to compute endogenous cost expressions in GAMs
- Replies: 3
- Views: 3399
Re: How to compute endogenous cost expressions in GAMs
Hi Renger, Thank you very much for your reply. Is there any math function to calculate the calculus expression I posted before? What I did was to compute the calculus and reverse function of the standard normal distribution in Mathematica before I put all those values are known scalar in GAMs. It wo...
- 5 years ago
- Forum: Modeling
- Topic: How to compute endogenous cost expressions in GAMs
- Replies: 3
- Views: 3399
How to compute endogenous cost expressions in GAMs
Capture.PNG Hi everyone, I saw some papers using GAMs to optimize a MINLP model(attached the obj for your consideration in the example of Liu et al (2010)). For the inventory holding cost, the computation is very complex involving calculus, normal distribution and then square root with decision var...
- 5 years ago
- Forum: Modeling
- Topic: Xii >= Xij how to code in GAMS
- Replies: 2
- Views: 3357
Re: Xii >= Xij how to code in GAMS
Hi Really appreciate your help! Have a good dayManassaldi wrote: ↑5 years ago Hi, it's simple
set i warehouse /1*3/;
alias(i,j);
eq(i,j)$(ord(i) ne ord(j)).. X(i,i) =g= X(i,j);
Bye