[gecode-users] BAB implementation

[aqwzsxaqwzsx]

I know that A * and CSP are different paradigms. I made several projects with both. Both are also used in the planning / scheduling problem. 
A * is easy to implement, simpler, and the variants are interesting when integrated in real-time systems. 
The CSP (with BAB engine) seems more suitable, but may require more time to be formalized, mapped to an existing solver. 
So, maybe both solutions should be tested and evaluated (development, complexity, maintainability, evolutivity,...)

Thanks,
Philippe 


> Le 13 mars 2018 à 16:10, Christian Schulte <cschulte at kth.se> a écrit :
> 
> A* and how BAB works in Gecode is very different. A* is typically based on representing the problem by states and then coming up with the right operators and functions, etc.
> 
> Gecode uses constraint programming which has a very different way of modeling problems. That's why I would suggest to really try a little bit of how models with constraint programming look like. If you want to get an idea on a more high-level you could try a modeling language such as MiniZinc:
>    http://www.minizinc.org/
> 
> Cheers
> Christian    
> 
> --
> Christian Schulte, https://chschulte.github.io/
> Professor of Computer Science, KTH, cschulte at kth.se
> Expert Researcher, RISE SICS, christian.schulte at ri.se
> 
> 
> -----Original Message-----
> From: aqwzsxaqwzsx at orange.fr [mailto:aqwzsxaqwzsx at orange.fr] 
> Sent: Tuesday, March 13, 2018 16:06
> To: users at gecode.org; Christian Schulte <cschulte at kth.se>
> Subject: RE: RE: [gecode-users] BAB implementation
> 
> 
> Hi,
> 
> Definitively not a homework. I have to make a technical choice to solve a planification problem with task/resources/scheduling.
> A * will be homogeneous with the rest of the software but CSP with a BAB engine seems clearly more appropriate to me.
> It has been proved in 1984 by Nau/Kumar/Kanal that A* is a special case of a general BAB formulation and I don't see any reason why it would not be the case with Gecode, but i was asking some advice to decide !
> Moreover, i will maybe have some questions about coding rules in gecode relative to embedded system. 
> 
> Philippe 
> 
> 
> ----------------
> Le 13/03/2018, à 15:16, "Christian Schulte" <cschulte at kth.se> a écrit :
> 
> Hi, I think you will have to do some reading. Smells like homework to me. Christian
> 
> --
> Christian Schulte, https://chschulte.github.io/ Professor of Computer Science, KTH, cschulte at kth.se Expert Researcher, RISE SICS, christian.schulte at ri.se
> 
> 
> -----Original Message-----
> From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On Behalf Of aqwzsxaqwzsx at orange.fr
> Sent: Tuesday, March 13, 2018 15:02
> To: users at gecode.org
> Subject: [gecode-users] BAB implementation
> 
> Hi all,
> 
> This is maybe a general question about the B&B and the A* algorithm, But I was wondering what was the advantage, force, weakness of the Gecode BAB engine over a A*. 
> 
> Thanks
> 
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