[Coin-discuss] Open-source Modeling Languages

[John Pye]

Sebastian Nowozin wrote:
> Are there any plans or directions for a more powerful open-source
> modeling language supporting the features of COIN-OR solvers? (similar
> to AMPL, GAMS, MathProg or ZIMPL, but open-source and
> license-compatible with COIN projects)
>   
Hi Sebastian,

I'm a member of a group working on a fairly powerful free open-source
mathematical modelling program called ASCEND.

ASCEND provides a modelling language similar to AMPL/GAMS, and currently
supports NLA, NLP and ODE/DAE solvers, as well as support for what we
call 'conditional models' which include if/else expressions, which may
or may not correspond to MINLP problems (I'm not sure). ASCEND also
provides object-oriented modelling syntax, so that a complex model can
be composed of refinements of simpler models. Models can be initialised
in a number of different ways, so that, for example, a 'forward' or
'backward' problem can be solved without changing any code in the model.
There is a GUI that allows you to play around with changing values in
your model, plotting results, etc.

I've done some preliminary work on linking ASCEND to IPOPT, but still
have a some work to do. Adding new solvers is quite straightforward in
general, but in the case of IPOPT I am having to do some work to provide
a sparse Hessian matrix calculation routine, and that still remains to
be done. And volunteers are very welcome, of course!

If you would like to give ASCEND a try, please contact me or take a look
at our wiki at
http://ascendwiki.cheme.cmu.edu.

Cheers
JP

-- 
John Pye
http://pye.dyndns.org/