sci.op-research

"SteveM" wrote in message
news:d15eb747-e935-411b-a050-584bca0617ab@n19g2000hsd.googlegroups.com...
> On Feb 12, 11:47 am, Christian Plum wrote:
>> Hi,
>>
>> I am looking to choose modelling software and a solver for an
>> commercial application. The problem will have some integer variables.
>>
>> A) The model to be implemented concerns minimization of a resource
>> cost and relies on two stochastic components, the prices and the
>> consumption. So I am looking for modelling software enabling me to
>> formulate a stochastic problem, relying on the software to be able to
>> convert it into a deterministic problem, solvable by standard solvers.
>>
>> B) For other projects I have used scripting modelling software as
>> GAMS. For the same project i needed to do a lot of preprocessing of
>> the data before giving it to GAMS. I found it really annoying that I
>> had to keep the preprocessing in one language (which was actually
>> capable of numeric manipulation) and construct the model in another
>> (where i could construct the model and match the indexes and sets
>> automatically). I would really like to find a way to do both..
>>
>> So I am trying to find modelling software that satisfies both A and B
>> and so far i have established that ILOG Cplex satisfy B through its
>> "concert technology" and that Mosel-Xpress satifies A, with its Xpress-
>> SP.
>>
>> So Im' asking, Is that correct? Cant I hope to satisfy both at the
>> same time ?
>>
>> Looking forward to your answers! ;)
>
> Let me return to the original problem which is pre-processing, not
> solver management during optimization. I happen to use MPL as my
> model manager. But the paradigm I've increasingly followed is
> separating data management from model management as much as I can. If
> you are into a data base to service the model for a penny, you are in
> for a pound. So you might as well leverage it's full capabilities
> because it's a lot easier to manipulate data on that platform than it
> is with GAMS or MPL.
>
> My models can be intermediate sized, and when I need to support one
> with a data base, I use Access. I can generate almost every input
> vector in Access using the Query Builder including index sets and pass
> those such that MPL merely reads in the data/indexes and passes those
> on to the with very little manipulation formulation. And error
> checking is much easier this way.
>
> I had a recent conversation with Bjarni Kristjansson from Maximal
> (MPL) and he acknowledged that his users have migrated in that
> direction. It just makes sense.
>
> SteveM

But how would your paradigm cope when you have data coming in from databases
of various types possibly scattered across many sites?
Bob Daniel