Hi Mattias,

Thanks for response. I will probably try patching it and send pull request.
Also this will get me more involved more in it :)
About the behavior, what should it be? `null` or a path starting from node
to itself? I couldn't find relevant documentation for it

Jatin

On Thu, Sep 18, 2014 at 1:21 PM, Mattias Persson <[email protected]>
wrote:

> Yup looks like a bug to me. I'm one of the authors of that algo
> implementation, so I'll see if I can have a look at it soon.
>
> On Tue, Sep 16, 2014 at 7:17 PM, Jatin Puri <[email protected]> wrote:
>
>> There is a bug <https://github.com/neo4j/neo4j/issues/2987> in
>> GraphAlgoFactory (trivial but never the less irritating). Basically if you
>> try finding a single shortest path from a node to itself, it gives
>> following behavior:
>>
>> Using  `GraphAlgoFactory.astar`, it throws:
>> org.neo4j.graphdb.NotFoundException: Relationship -1 not found
>>
>> Using `GraphAlgoFactory.dijskstra`, it returns:
>> A Path starting (WeightedPath#startNode) from the node and ending
>> (WeightedPath#endNode) at itself but with no relationship between them.
>>
>> I looked at the source and found the bug in each and was rectifying it.
>> But I am not sure what the behavior should be.
>>
>> Documentation
>> <https://github.com/neo4j/neo4j/blob/master/community/graph-algo/src/main/java/org/neo4j/graphalgo/PathFinder.java>
>>  says
>> that it should return null if no path is found. But for a path from a node
>> to itself, should we assume it as a self-loop with no weight, given there
>> is no explicit relationship between node to itself? Or is the behavior of
>> `dijkstra` correct? (I think its wrong)
>>
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>
>
>
> --
> Mattias Persson
> Neo4j Hacker at Neo Technology
>
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-- 
Jatin Puri
http://jatinpuri.com <http://www.jatinpuri.com>

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