Fw: [Coin-discuss] Open-source Modeling Languages

[Jun Ma]

Don't think the following email is posted to the discussion list.
But it points out the two commercial modeling system that have integrated OS 
support in their releases, besides AMPL which integration with OS is not 
released.


>> Thanks for alerting me to this. I've got a few questions, I hope that's
>> OK? You mention that OS can be used to hook modelling languages to
>> solvers. Can you detail what happens on the modelling-langauge end of
>> the hookup? Are symbolic equation structures transferred, or is it an
>> evaluation/callback type arrangement? What sort of API do you provide?
>> What modelling languages have been hooked up so far?
>
> The API has three types of methods:
>
> 1) get methods
> 2) set/add methods
> 3) calculate methods
>
> A modeling language could link to the libOS and use the set/add methods to 
> create an in-memory OSInstance object. The OSInstance object could then be 
> read into our OSiLWriter to actually write the XML file.
>
> In OS/src/OSModelInterfaces/OSnl2osil.cpp we illustrate this and take the 
> AMPL nl representation and create a corresponding OSInstance object.
> In addition to AMPL, Mosek
>
> http://www.mosek.com/fileadmin/products/5_0/tools/doc/html/capi/node025.html
>
> supports our output.
>
> So does Frontline systems in their Solver Platform SDK
>
> http://www.solver.com/sdkplatform.htm
>
> However, you can also use our calculate methods which are hooked up to 
> CppAD for evaluation/callbacks.
>
> The API and XML format is described here (this should answer a lot of your 
> questions)
>
> https://www.coin-or.org/OS/publications/OSiL1.pdf
>
>
>>
>> Also, is there any overlap between OS and the CAPE-OPEN optimisation
>> API? Is there a performance hit from encoding optimisation models using
>
> I am not familiar enough with CAPE-OPEN to answer your question.
>
>> XML? Are there plans to generalise the OS approach to other types of
>
> I don't think the XML performance hit is any greater than other formats 
> such as MPS. We have written dedicated parsers for the XML format which 
> are very fast.
>
>> problems such as ODE/DAE, NLA, etc (and how does OS mesh with other COIN
>> projects NLAPI and OSI)? Finally, is there provision for supplying
>> 'external' equations/constraints/relations, for example embedded as
>> routines in DLLs?
>
> We do not have a representation scheme for ODE. I do not know what DAE and 
> NLA are. OS is written from an optimization standpoint. We are open to 
> extensions.
>
> Think of OS as an extension of OSI to nonlinear optimization. OS links 
> with Osi and uses it to call Osi compatible solvers.
>
> I don't understand the last question above with the external DLLs?
>
>
>>
>> I'd also alert you that your project is not listed here, which perhaps
>> it should be:
>> http://www.coin-or.org/projects/
>
> Thanks -- it is now fixed.
>
> Cheers,
>
>
> -- 
> Kipp Martin
> Professor of Operations Research
> and Computing Technology
> Graduate School of Business
> University of Chicago
> 5807 South Woodlawn Avenue
> Chicago, IL 60637
> 773-702-7456
> kipp.martin at chicagogsb.edu
> http://gsbkip.chicagogsb.edu
> http://www.coin-or.org
>