jgrapht-users — JGraphT user list.

[jgrapht-users] problem with random graph generation

[andrea p. <pag...@gm...>]

Hi everybody,

I'm trying to generate random graphs using the provided set of functions in
JGrapht, actually the code im using is:


/*************************************************************************************************************************************************************/

RandomGraphGenerator<String, DefaultEdge> randomGenerator = new
RandomGraphGenerator<String, DefaultEdge>(5, 5);
Graph<String, DefaultEdge> randomGraph = new SimpleGraph<String,
DefaultEdge>(DefaultEdge.class);
VertexFactory<String> factory = new
ClassBasedVertexFactory<String>(String.class);
randomGenerator.generateGraph(randomGraph, factory, null);

/***********************************************************************************************************************************************************/

it's just an example creating a random graph with 5 nodes and 5 edges.

the program get stuck when invoking
"randomGenerator.generateGraph(randomGraph, factory, null);" any idea?
I think I miss something with the factory...help is really appreciated!

Thanks in advance.


Best regards,

Andrea

Re: [jgrapht-users] Create Edge

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

http://www.jgrapht.org/javadoc/org/jgrapht/Graph.html#containsEdge(V,%20V)

JVS

J. Allen Q. Santos wrote:
> Hi,
>  
> I have an instance of a Simple Directed Graph which has already been 
> populated with vertices and edges. What I'm trying to do is, given 2 
> vertices, check whether an edge connecting the vertices exists.
>  
> *** sample code ***
> Object[] o = simpledirectedgraph.getEdges();
> EdgeFactory ef = simpledirectedgraph.getEdgeFactory();
> Object edge = ef.createEdge(source,target);
> for( int i = 0 ; i < o.length ; i++ ) {
>     if(edge.equals(o[i])) {
>         System.out.println("Edge EXISTS!");
>     }
> }
>  
>  
> Is there any other way? It seems that the code above doesn't work.
>  
> Thank you very much.
>  
>  
> Allen
> 
> 
> ------------------------------------------------------------------------
> 
> ------------------------------------------------------------------------------
> The Planet: dedicated and managed hosting, cloud storage, colocation
> Stay online with enterprise data centers and the best network in the business
> Choose flexible plans and management services without long-term contracts
> Personal 24x7 support from experience hosting pros just a phone call away.
> http://p.sf.net/sfu/theplanet-com
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> jgrapht-users mailing list
> jgr...@li...
> https://lists.sourceforge.net/lists/listinfo/jgrapht-users

[jgrapht-users] Create Edge

[J. A. Q. S. <jqs...@ms...>]

Hi,

I have an instance of a Simple Directed Graph which has already been populated with vertices and edges. What I'm trying to do is, given 2 vertices, check whether an edge connecting the vertices exists.

*** sample code ***
Object[] o = simpledirectedgraph.getEdges();
EdgeFactory ef = simpledirectedgraph.getEdgeFactory();
Object edge = ef.createEdge(source,target);
for( int i = 0 ; i < o.length ; i++ ) {
    if(edge.equals(o[i])) {
        System.out.println("Edge EXISTS!");
    }
}


Is there any other way? It seems that the code above doesn't work.

Thank you very much.


Allen

Re: [jgrapht-users] info on cloning undirected graph

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

There is a clone() on AbstractBaseGraph (see 
testsrc/org/jgrapht/graph/CloneTest.java), and also a utility method 
org.jgrapht.Graphs.addGraph which can be used to copy the contents of 
one graph into a new empty graph.

JVS

andrea pagani wrote:
> Hi everybody,
> 
> It's me again, well I need to have a copy of my graph to work on without 
> reflecting the changing on the original one.
> I saw that UndirectedGraph class has no implementation of clone() 
> method. My idea is the to extract the edgeFactory from the original one 
> and build a SimpleGraph from that edgeFactory.
> Do you think it's correct?
> My issue is the edgeFactory I get from the original graph is empty...and 
> so the simpleGraph I then create is empty as well...
> 
> 
> Any suggestion is more than welcome.
> 
> 
> Thank you in advance.
> 
> 
> Best Regards,
> 
> Andrea
> 
> 
> 
> PS: as you might see I'm not an experienced java programmer!
> 
> 
> ------------------------------------------------------------------------
> 
> ------------------------------------------------------------------------------
> The Planet: dedicated and managed hosting, cloud storage, colocation
> Stay online with enterprise data centers and the best network in the business
> Choose flexible plans and management services without long-term contracts
> Personal 24x7 support from experience hosting pros just a phone call away.
> http://p.sf.net/sfu/theplanet-com
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> jgrapht-users mailing list
> jgr...@li...
> https://lists.sourceforge.net/lists/listinfo/jgrapht-users

[jgrapht-users] info on cloning undirected graph

[andrea p. <pag...@gm...>]

Hi everybody,

It's me again, well I need to have a copy of my graph to work on without
reflecting the changing on the original one.
I saw that UndirectedGraph class has no implementation of clone() method. My
idea is the to extract the edgeFactory from the original one and build a
SimpleGraph from that edgeFactory.
Do you think it's correct?
My issue is the edgeFactory I get from the original graph is empty...and so
the simpleGraph I then create is empty as well...


Any suggestion is more than welcome.


Thank you in advance.


Best Regards,

Andrea



PS: as you might see I'm not an experienced java programmer!

Re: [jgrapht-users] Shortest path, alternatives?

[Alessandro M. B. <a.m...@gm...>]

ok, just downloaded the 703 revision from the svn, as i read about some
optimizations in the floyd warshall code...
I tried Floyd-Warshall with a 1000 vertex / 2000 edges graph and it
completed in less than 2 minutes on the same machine as above.
Using repeated(n^2) Dijkstra invocations, my overall time complexity was
O(n^4) and now is O(n^3), which is more acceptable.

I will try with increasingly bigger graph sizes and keep you informed.

Alessandro


2010/1/29 andrea pagani <pag...@gm...>

> Hi Alessandro,
>
> I'm using FloydWarshall on samples about 200 nodes and it works pretty
> well, but you have a far bigger sample.
> Give it a try.
> Let me know if it's fast even with this big sample.
>
> Thanks,
>
> Andrea
>
> On Fri, Jan 29, 2010 at 6:37 PM, Alessandro Marco Boutari <
> a.m...@gm...> wrote:
>
>> hey it's exactly what i need! I wasn't aware of the existence of this
>> algorithm! Thank you very much, I'll try it asap.
>>
>> Alessandro
>>
>> Il 29/01/2010 18.30, John V. Sichi ha scritto:
>> > Have you tried the FloydWarshallShortestPaths implementation in JGraphT?
>> >
>> > JVS
>> >
>> > Alessandro Marco Boutari wrote:
>> >> Hello everybody,
>> >>
>> >> I am using the JgraphT library in a project related to document
>> >> indexing. At some point I need to find the shortest path between all
>> >> the possible vertex pairs, and this is a serious bottleneck: given a
>> >> graph with 800 vertex and 2000 edges, it takes about 30 minutes on a
>> >> Mac dual core (already taken into account some multithreading and
>> >> calculating only half the distance matrix) to complete the full
>> >> calculation and this is only a test graph, the useful ones are much
>> >> bigger than that.
>> >>
>> >> So I would like to know:
>> >>
>> >> 1) can you confirm the actual implementation of dijkstra shortest
>> >> path has a complexity of O(n^2)?
>> >> 2) I had a look at the code and it seems that it calculates for each
>> >> node a spanning tree. Could it be possible to modify the code to make
>> >> it return a one-to-all shortest path calculation?
>> >> 3) are there any better alternatives to dijkstra
>> >> algorithm/implementation?
>> >> 4) if answer to 3) is yes, would they be compatible with the graph
>> >> representation used in JgraphT?
>> >>
>> >> thank you in advance
>> >> Alessandro
>> >>
>> >>
>> >>
>> ------------------------------------------------------------------------
>> >>
>> >>
>> ------------------------------------------------------------------------------
>> >>
>> >> The Planet: dedicated and managed hosting, cloud storage, colocation
>> >> Stay online with enterprise data centers and the best network in the
>> >> business
>> >> Choose flexible plans and management services without long-term
>> >> contracts
>> >> Personal 24x7 support from experience hosting pros just a phone call
>> >> away.
>> >> http://p.sf.net/sfu/theplanet-com
>> >>
>> >>
>> >>
>> ------------------------------------------------------------------------
>> >>
>> >> _______________________________________________
>> >> jgrapht-users mailing list
>> >> jgr...@li...
>> >> https://lists.sourceforge.net/lists/listinfo/jgrapht-users
>> >
>>
>>
>> ------------------------------------------------------------------------------
>>
>> The Planet: dedicated and managed hosting, cloud storage, colocation
>> Stay online with enterprise data centers and the best network in the
>> business
>> Choose flexible plans and management services without long-term contracts
>> Personal 24x7 support from experience hosting pros just a phone call away.
>> http://p.sf.net/sfu/theplanet-com
>> _______________________________________________
>> jgrapht-users mailing list
>> jgr...@li...
>> https://lists.sourceforge.net/lists/listinfo/jgrapht-users
>>
>
>

Re: [jgrapht-users] information about FloydWarshallShortestPaths class and methods

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

Andrea, thanks for the test case.  There was indeed a bug, which it 
turns out was already fixed in the latest code in Subversion as part of 
Soren Davidsen's rewrite of the algorithm implementation to make it more 
efficient.  The fix will be included in the next release of JGraphT.

I'm adding your test case to the unit test suite.

JVS

John V. Sichi wrote:
> andrea pagani wrote:
>> Hello everybody,
>>
>> I'm very new to JgraphT and to this mailinglist too.
>> I'm trying to compute the diamater of a very simple graph:
>> ?ui=2&view=att&th=126657e30cb18cc8&attid=0.1&disp=attd&realattid=ii_126657e30cb18cc8&zw 
>>
>>
>> using the FloydWarshallShortestPaths<V,E> class and getDiameter() method.
>> It returns me infinity, that is not correct....is there something I'm 
>> missing?
>>
>> Thank you very much in advance.
> 
> Could be a bug, but it would help if you submitted the Java code for 
> your unit test so that we can reproduce it, debug/fix, and then make 
> sure it stays fixed by including your test in the suite.
> 
> JVS
> 

Re: [jgrapht-users] Shortest path, alternatives?

[Alessandro M. B. <a.m...@gm...>]

hey it's exactly what i need! I wasn't aware of the existence of this 
algorithm! Thank you very much, I'll try it asap.

Alessandro

Il 29/01/2010 18.30, John V. Sichi ha scritto:
> Have you tried the FloydWarshallShortestPaths implementation in JGraphT?
>
> JVS
>
> Alessandro Marco Boutari wrote:
>> Hello everybody,
>>
>> I am using the JgraphT library in a project related to document 
>> indexing. At some point I need to find the shortest path between all 
>> the possible vertex pairs, and this is a serious bottleneck: given a 
>> graph with 800 vertex and 2000 edges, it takes about 30 minutes on a 
>> Mac dual core (already taken into account some multithreading and 
>> calculating only half the distance matrix) to complete the full 
>> calculation and this is only a test graph, the useful ones are much 
>> bigger than that.
>>
>> So I would like to know:
>>
>> 1) can you confirm the actual implementation of dijkstra shortest 
>> path has a complexity of O(n^2)?
>> 2) I had a look at the code and it seems that it calculates for each 
>> node a spanning tree. Could it be possible to modify the code to make 
>> it return a one-to-all shortest path calculation?
>> 3) are there any better alternatives to dijkstra 
>> algorithm/implementation?
>> 4) if answer to 3) is yes, would they be compatible with the graph 
>> representation used in JgraphT?
>>
>> thank you in advance
>> Alessandro
>>
>>
>> ------------------------------------------------------------------------
>>
>> ------------------------------------------------------------------------------ 
>>
>> The Planet: dedicated and managed hosting, cloud storage, colocation
>> Stay online with enterprise data centers and the best network in the 
>> business
>> Choose flexible plans and management services without long-term 
>> contracts
>> Personal 24x7 support from experience hosting pros just a phone call 
>> away.
>> http://p.sf.net/sfu/theplanet-com
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> jgrapht-users mailing list
>> jgr...@li...
>> https://lists.sourceforge.net/lists/listinfo/jgrapht-users
>

Re: [jgrapht-users] Shortest path, alternatives?

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

Have you tried the FloydWarshallShortestPaths implementation in JGraphT?

JVS

Alessandro Marco Boutari wrote:
> Hello everybody,
> 
> I am using the JgraphT library in a project related to document 
> indexing. At some point I need to find the shortest path between all the 
> possible vertex pairs, and this is a serious bottleneck: given a graph 
> with 800 vertex and 2000 edges, it takes about 30 minutes on a Mac dual 
> core (already taken into account some multithreading and calculating 
> only half the distance matrix) to complete the full calculation and this 
> is only a test graph, the useful ones are much bigger than that.
> 
> So I would like to know:
> 
> 1) can you confirm the actual implementation of dijkstra shortest path 
> has a complexity of O(n^2)?
> 2) I had a look at the code and it seems that it calculates for each 
> node a spanning tree. Could it be possible to modify the code to make it 
> return a one-to-all shortest path calculation?
> 3) are there any better alternatives to dijkstra algorithm/implementation?
> 4) if answer to 3) is yes, would they be compatible with the graph 
> representation used in JgraphT?
> 
> thank you in advance
> Alessandro
> 
> 
> ------------------------------------------------------------------------
> 
> ------------------------------------------------------------------------------
> The Planet: dedicated and managed hosting, cloud storage, colocation
> Stay online with enterprise data centers and the best network in the business
> Choose flexible plans and management services without long-term contracts
> Personal 24x7 support from experience hosting pros just a phone call away.
> http://p.sf.net/sfu/theplanet-com
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> jgrapht-users mailing list
> jgr...@li...
> https://lists.sourceforge.net/lists/listinfo/jgrapht-users

[jgrapht-users] Shortest path, alternatives?

[Alessandro M. B. <a.m...@gm...>]

Hello everybody,

I am using the JgraphT library in a project related to document indexing. At
some point I need to find the shortest path between all the possible vertex
pairs, and this is a serious bottleneck: given a graph with 800 vertex and
2000 edges, it takes about 30 minutes on a Mac dual core (already taken into
account some multithreading and calculating only half the distance matrix)
to complete the full calculation and this is only a test graph, the useful
ones are much bigger than that.

So I would like to know:

1) can you confirm the actual implementation of dijkstra shortest path has a
complexity of O(n^2)?
2) I had a look at the code and it seems that it calculates for each node a
spanning tree. Could it be possible to modify the code to make it return a
one-to-all shortest path calculation?
3) are there any better alternatives to dijkstra algorithm/implementation?
4) if answer to 3) is yes, would they be compatible with the graph
representation used in JgraphT?

thank you in advance
Alessandro

Re: [jgrapht-users] information about FloydWarshallShortestPaths class and methods

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

andrea pagani wrote:
> Hello everybody,
> 
> I'm very new to JgraphT and to this mailinglist too.
> I'm trying to compute the diamater of a very simple graph:
> ?ui=2&view=att&th=126657e30cb18cc8&attid=0.1&disp=attd&realattid=ii_126657e30cb18cc8&zw
> 
> using the FloydWarshallShortestPaths<V,E> class and getDiameter() method.
> It returns me infinity, that is not correct....is there something I'm 
> missing?
> 
> Thank you very much in advance.

Could be a bug, but it would help if you submitted the Java code for 
your unit test so that we can reproduce it, debug/fix, and then make 
sure it stays fixed by including your test in the suite.

JVS

[jgrapht-users] minimum spanning tree using closestfirstiterator

[Christian M. <chr...@ig...>]

hey
as first i have to say that i have not much experience in java programming.
the problem is as follows:

i have a defaultdirectedweighted graph of the type 
<ThoughtSpaceVertex<Long,String,URL>,DefaultWeightedEdge>. I would like 
to get the minimum spanning tree of this graph and found that i would 
have to use the closestfirstiterator for this problem. can anybody help 
me how to use the iterator? maybe with a small code example?

thanks in advance
christian

[jgrapht-users] wiki move

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

As part of the ongoing transition of JGraphT to live under the Eigenbase 
umbrella, I've moved the old wiki content over to the Eigenbase wiki 
(aka Eigenpedia).

So, http://wiki.jgrapht.org, which used to redirect to 
http://jgrapht.wikispaces.com, now redirects to 
http://pub.eigenbase.org/wiki/JGraphT:Docs.

I've deleted jgrapht.wikispaces.com since Google didn't show too many 
links directly to it.  If you were using a wikispaces account and want 
to update some JGraphT wiki content, contact me and I'll create an 
Eigenpedia account for you.

Eigenpedia runs mediawiki, which in my opinion is a bit easier to deal 
with than wikispaces, although it assumes you like text editing (no 
visual editor).

JVS

[jgrapht-users] shutting off the users forum on sourceforge.net

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

Hi all,

Since the beginning of the project, JGraphT has had both a users mailing 
list (this one) and a user forum.  I have always found it to be a pain 
to respond to the forum posts, and they are not very good for knowledge 
sharing since unlike this list, usually only I and maybe a few other 
people actually subscribe to them.

As a result, I'm going to shut off the forums (I've already redirected 
the preferred support mechanism to this list a while back).

At the same time, I'm setting up nabble mirroring for this mailing list, 
which means it will finally get indexed by Google, and the nabble 
archive browsing UI is a bit friendlier than the sf.net UI.  You don't 
need to do anything in response; this is just a read-only mirror, and 
the sf.net mailman remains the place to post new messages.

I'm working on importing the archives from sf.net's mailman; all new 
posts will get incremantally added automatically via a subscription from 
nabble.

Here's a link to the new nabble mirror:

http://n3.nabble.com/jgrapht-users-f107614.html

(You'll only see old posts in it once the import completes.)

I'll see if they can also take an import of the old forum content, which 
is going to become inaccessible once I shut it off (unfortunately sf.net 
does not support putting a forum into public read-only mode).

JVS

[jgrapht-users] adapter to org.eclipse.draw2d.graph

[Stella L. <ste...@ya...>]

Hi, jgrapht-users.
I am new to jgrapht. I develop RCP application under eclipse platform and would like to 
integrate jgrapht with it. Is there a jgrapht adapter for org.eclipse.draw2d.graph package?
If no, is it difficult to create one? Does it make sense to visualize with draw2d.graph ?
Thanks, Stella


      

[jgrapht-users] Could i create an edge with different color

[Vu H. T. <th...@gm...>]

Hi,
How can i create an edge with different color. I'm using jgrapht for my
modelisation about PERT. I want my critic path having a color red
thanks

Re: [jgrapht-users] finding all paths from one vertex to another

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

guille lists wrote:
> I want to find all possible paths between two vertex in a
> SimpleDirectedGraph (no loops and no multiple edges). I was going to
> do it using the DepthFirstIterator, but I'm just wondering if there is
> already a way to do it with JGraphT. I've seen the KShortestPath
> algorithm, but I'm not sure if it is appropriate for what I want since
> I just need all path (so I thought it may be easier to get them from a
> DFS). Anyway, I'll appreciate some suggestion since I'm new JGraphT
> and i'm not yet very familiar with its API.

This question comes up a lot...for an arbitary graph, the number of 
paths between two vertices can be huge (consider a complete graph, for 
instance), so we don't provide a method for it.  I'll bet there's some 
value of K above which you wouldn't want to get any more :)

JVS

[jgrapht-users] finding all paths from one vertex to another

[guille l. <gui...@gm...>]

Hi,

I want to find all possible paths between two vertex in a
SimpleDirectedGraph (no loops and no multiple edges). I was going to
do it using the DepthFirstIterator, but I'm just wondering if there is
already a way to do it with JGraphT. I've seen the KShortestPath
algorithm, but I'm not sure if it is appropriate for what I want since
I just need all path (so I thought it may be easier to get them from a
DFS). Anyway, I'll appreciate some suggestion since I'm new JGraphT
and i'm not yet very familiar with its API.

thanks,

guille

[jgrapht-users] jgrapht vertex shape / applets & swing windowds

[Simon F. <S.F...@su...>]

Dear All,
I have recently been recommended jgrapht and it looks great.
I hope to be able to visualize some networks and to begin with have  
been looking at the "source code of the applet" example (http://jgrapht.sourceforge.net/visualizations.html 
)
This is running as expected, however I have two questions:
1 - how can I control the shape of the nodes, I was hoping to be able  
to use small circles - however, I haven't been able to work out how
2 - is it possible to change this from an applet to a regular swing  
window?
If anyone can provide any help of these matters, I would be most  
thankful
all the best
si

Re: [jgrapht-users] Windows vs. Unix Version

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

David Hosier wrote:
> I'm interested in using JGraphT, but I'm curious why there is a  
> version for Windows and a version for Unix and what the difference  
> is.  I tried searching the forum.  Maybe I missed it somewhere?  Is it  
> just the fact that they are packaged as different archive types?

Yes, just different archiving.

JVS

[jgrapht-users] Windows vs. Unix Version

[David H. <hos...@me...>]

I'm interested in using JGraphT, but I'm curious why there is a  
version for Windows and a version for Unix and what the difference  
is.  I tried searching the forum.  Maybe I missed it somewhere?  Is it  
just the fact that they are packaged as different archive types?

Thanks,
David

Re: [jgrapht-users] DijkstraShortestPath inefficient for (start, *) ?

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

kevin brintnall wrote:
> On Thu, Oct 22, 2009 at 07:37:15PM -0700, John V. Sichi wrote:
>> The Dijkstra API class is just a thin wrapper around 
>> ClosestFirstIterator, which already provides what you need (as well as 
>> the MST), though not perfectly wrapped.
> 
> John,
> 
> You're right; that's probably what I'll end up doing.
> 
> Do you think it makes sense to modify/augment JGraphT's existing Dijkstra
> module to do this?  Or add a second Dijkstra implementation to JGraphT?
> This seems like a common use case.

If someone wants to work out a clean interface for it, we can certainly 
add it in.

JVS

Re: [jgrapht-users] DijkstraShortestPath inefficient for (start, *) ?

[kevin b. <kb...@ru...>]

On Thu, Oct 22, 2009 at 07:37:15PM -0700, John V. Sichi wrote:
> The Dijkstra API class is just a thin wrapper around 
> ClosestFirstIterator, which already provides what you need (as well as 
> the MST), though not perfectly wrapped.

John,

You're right; that's probably what I'll end up doing.

Do you think it makes sense to modify/augment JGraphT's existing Dijkstra
module to do this?  Or add a second Dijkstra implementation to JGraphT?
This seems like a common use case.

-- 
 kevin brintnall =~ /kb...@ru.../


> JVS
> 
> kevin brintnall wrote:
> > Hello,
> > 
> > JGraphT's existing Dijkstra API is able to search for a single (start,end)
> > vertex pair.  However, it doesn't appear there is a good way to calculate
> > all paths from a single source vertex: i.e. (source,*).
> > 
> > Whereas the ideal run-time of Dijkstra's algorithm is O(E + V log(V)), it
> > appears the best run-time with JGraphT's current API is O(V * ideal) for
> > this use case.
> > 
> > Maybe it's better to allow endVertex==null, and calculate the weight and
> > predecessor maps for every vertex in that case?
> > 
> > Any suggestions?  Am I missing a good alternative?
> > 

Re: [jgrapht-users] DijkstraShortestPath inefficient for (start, *) ?

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

The Dijkstra API class is just a thin wrapper around 
ClosestFirstIterator, which already provides what you need (as well as 
the MST), though not perfectly wrapped.

JVS

kevin brintnall wrote:
> Hello,
> 
> JGraphT's existing Dijkstra API is able to search for a single (start,end)
> vertex pair.  However, it doesn't appear there is a good way to calculate
> all paths from a single source vertex: i.e. (source,*).
> 
> Whereas the ideal run-time of Dijkstra's algorithm is O(E + V log(V)), it
> appears the best run-time with JGraphT's current API is O(V * ideal) for
> this use case.
> 
> Maybe it's better to allow endVertex==null, and calculate the weight and
> predecessor maps for every vertex in that case?
> 
> Any suggestions?  Am I missing a good alternative?
> 

[jgrapht-users] DijkstraShortestPath inefficient for (start,*) ?

[kevin b. <kb...@ru...>]

Hello,

JGraphT's existing Dijkstra API is able to search for a single (start,end)
vertex pair.  However, it doesn't appear there is a good way to calculate
all paths from a single source vertex: i.e. (source,*).

Whereas the ideal run-time of Dijkstra's algorithm is O(E + V log(V)), it
appears the best run-time with JGraphT's current API is O(V * ideal) for
this use case.

Maybe it's better to allow endVertex==null, and calculate the weight and
predecessor maps for every vertex in that case?

Any suggestions?  Am I missing a good alternative?

-- 
 kevin brintnall =~ /kb...@ru.../