jgrapht-developers — A discussion list for JGraphT developers.

[jgrapht-developers] listener list cloning

[John V. S. <js...@ya...>]

DefaultListenableGraph.clone clones the lists of listeners and 
associates them with the cloned graph.  Is this correct?  If I ask to 
listen to a graph, that doesn't mean I want to listen to its clones that 
I don't even know about.

JVS

[jgrapht-developers] edge ownership

[John V. S. <js...@ya...>]

Graph.java has the following comment:

"This library works best when vertices represent arbitrary objects and 
edgesrepresent the relationships between them. While vertex instances 
are expected to be included in more than one graph, edges are generally 
assumed to be exclusive to one graph. The method 
<code>addEdge(Edge)</code> provides a back-door for that assumption and 
a programmer must exercise care if decided to use it."

What is the reason for the edge ownership exclusivity?  Allowing edges 
to be aliased in more than one graph is generally useful (especially if 
they have some additional information associated with them).  And view 
graphs like SubGraph and AsUndirectedGraph implicitly violate the 
ownership rule.

Anyway, it seems like it should be a hard rule one way or the other, not 
just a "general assumption."

JVS

Re: [jgrapht-developers] Dijkstra, ShortestPath and simple TSP Alg

[John V. S. <js...@ya...>]

Stuart and I were discussing a related topic offline (performance vs. 
genericity).  Using multiple implementations, we could leave it up to 
the user to decide, although that means more to maintain.  When Barak 
gets back, let's see where he wants to go with all of this.

JVS

Michael Behrisch wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hello,
> 
> I checked some source code and unfortunately noticed only afterwards 
> that there is already a Dijkstra (and even a FibonnacciHeap). I would
> like to have different heaps, because in practice the Fibo is often
> slower than a simple BinaryHeap (although this one does not meet
> the hard runtime bounds). Maybe we move the heap package one up
> and let runtime-tests decide which of the implementations of the Fibo 
> to choose?
> 
> Michael
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> 
> 
> -------------------------------------------------------
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> Welcome to geek heaven.
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[jgrapht-developers] Dijkstra, ShortestPath and simple TSP Alg

[Michael B. <beh...@in...>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello,

I checked some source code and unfortunately noticed only afterwards 
that there is already a Dijkstra (and even a FibonnacciHeap). I would
like to have different heaps, because in practice the Fibo is often
slower than a simple BinaryHeap (although this one does not meet
the hard runtime bounds). Maybe we move the heap package one up
and let runtime-tests decide which of the implementations of the Fibo 
to choose?

Michael
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Version: GnuPG v1.0.7 (GNU/Linux)

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sBHEV+QMBcVJHn7dsqP7yDg=
=Gfpr
-----END PGP SIGNATURE-----

[jgrapht-developers] RE: [jgrapht - Users] simple, multi, pseudo, directed

[Barak N. <ba...@3p...>]

In second thought, the guy has a point. The AbstractBaseGraph is
non-instantiable. Perhaps should be called "AdjacencyListGraph" and made
instantiable (non-abstract)?




> -----Original Message-----
> From: SourceForge.net [mailto:no...@so...]
> Sent: Thursday, September 04, 2003 08:25
> To: no...@so...
> Subject: [jgrapht - Users] simple, multi, pseudo, directed
>=20
>=20
> Read and respond to this message at:
> https://sourceforge.net/forum/message.php?msg_id=3D2177962
> By: nobody
>=20
> In graph theory, I am well aware of the distinction between simple, =
multi,
> etc.
>=20
> However, when it comes to implementation, I am wondering why you chose =
to
> divide
> them up.  Could you not come up with a single data structure to handle =
all
> the
> cases?

[jgrapht-developers] jgrapht-developer mailing list

[Barak N. <ba...@cs...>]

I think that for developers the mailing list provides a more convenient
alternative to the forum (allows to attach files and to work from the email
client).

Postings are archived on the website similarly to the forum and should
appear at http://sourceforge.net/mail/?group_id=86459.

Barak