[Cbc] Getting Started

[Alex Escott]

Thanks Ian... that simple BAB sample makes a lot more sense!

My problem now is that the objective (double obj[] = { 1.0, 1.0 };) represents a mathematical equation. My objective/evaluation function is external, it comes from inputting varying ranges of x0, x1 into a program and the program spits out a number. I want to maximize this number with constraints on x0 and x1.

Is this possible with CBC?



-----Original Message-----
From: Iain Dunning [mailto:iaindunning at gmail.com] 
Sent: August-04-11 5:10 PM
To: Alex Escott
Cc: cbc at list.coin-or.org
Subject: Re: [Cbc] Getting Started

Hey,
Try looking at https://projects.coin-or.org/Cbc/browser/trunk/Cbc/examples/simpleBAB.cpp
and the other examples in that folder.
Especially line 25 to line 42. There are some examples in the CLP repository too that are similar I think.

Its pretty baffling at a first look, and I've personally never built a model in memory (although I think I'm going to try today!), but I think you'll be able to work it out from the examples.
Oh and .MPS, like .LP, is a file format for describing the formulation of a linear programme.
Good luck!

Cheers,
Iain

On 5 August 2011 05:23, Alex Escott <AE at malaspina-labs.com> wrote:
>
> Hi all, new to CBC and trying to get something simple (I think!) working. I have an objective function and set of parameters which is pretty small in comparison to the 1000s of params that I see people talking about.
>
> My params will be integer, floating point, or Boolean, and they don't have any constraints between them. I only have ranges for the values themselves. I have only 10-15 of these. They look something like:
>
> int     num1, where 0 <= num1 <= 20
> float num2, where -1.0 <= num2 <= 1.0
> bool num3, where num3 == 0 or 1 (true or false)
>
> I've spent the last day or two going through the code, docs and examples and am still wondering how to get started...
>
> 1. What class do I create for my solution? A CBCSolver?
> 2. How are these .mps files created... are they a serialized state of the solver, or do I create one from scratch to start?
> 3. How do I declare my params and their types/bounds and input them to the solver?
> 4. How do I hook up my objective function?
>
> Any help is greatly appreciated, thanks a lot!
>
> -ake
>
>
> _______________________________________________
> Cbc mailing list
> Cbc at list.coin-or.org
> http://list.coin-or.org/mailman/listinfo/cbc



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Iain Dunning
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