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7

complex Pyomo MINLP to NEOS using Couenne. So, I had to Google a bit to understand this part as I am not familiar with the package nor the NEOS service. It would be beneficial as to where in the run-time progress you get the error message and what it exactly states. From the NEOS webpage I found the following limitations Retrieving results If you ...


6

To create a MPS file using GAMS, you have two options as follows: Your first option is to use the CONVERT solver. AFAIK, this solver is not available on NEOS Server (see here for a list of available solvers). Your second option is to use the solver-specific options to create MPS files. For example, CPLEX has a writemps option, which allows you to generate a ...


5

It is highly dependent to the problem, and to the size of the instance you are solving. For example, in many scheduling problems I have dealt with, the optimal solution cannot be found within 8 hours for medium-sized instances. Recently, I have been using NEOS server since I didn't have access to my uni PC as a result of quarantine! I had an MILP model for ...


4

I found it hard, using Pyomo, to get that kind of information since Pyomo's results object has a different structure depending on the solver that has been used. To get around that, I consider that the ugly solution is still the most reliable one up to now, until someone shows me a better way. Convert the results object that was returned by the solve() ...


2

In my experience I have run some very large scale problems for 8+ hours with over 500K+ binary variables due computational issues because of not having larger RAMs. In around 2008, cloud computing was just starting and availability of machines with huge RAMs was hard to find unlike these days where we can just swipe a credit card on AWS. I would be surprised ...


2

It is totally normal for some instances to take more than hours to be solved(and that's why NEOS Server has the limitation of 8 hours for each instance to be able to serve more users). The thing that you can try is starting your solving process with multi-start(which is one of many options that are available with Knitro on NEOS). 'ms_enable'=1 is the option ...


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