Re: [Tm4j-developers] Graph presentation

[Murray A. <m.a...@op...>]

Kal Ahmed wrote:

> At 09:22 27/02/2002 -0800, Jack Park wrote:
> 
>> It may be that this group is familiar with 
>> http://touchgraph.sourceforge.net. (Apache)
> 
> I have had a brief discussion with Alex Shapiro (developer of 
> Touchgraph) about using it as a visualisation for a topic map in TM4J. 
> Since that discussion I kind of got bogged down in 0.6.0 release stuff. 
> But now that the TMNav application is back on the cards I will resume 
> experimenting with it.


I have a preliminary XTM-to-TouchGraph converter working, though it is
missing a good deal of the topic map (such as occurrences and any sort
of interactive features). As a display tool for topics, associations,
and *some* of the scopes it works passably. But for now I won't be
spending so much time on it as my Ph.D duties are calling louder. But
perhaps working together on a Java API for XTM-in-TG I'd be happy to
lend a hand.


>> Another one I just discovered (though others may be familiar with it) 
>> is http://jgraph.sourceforge.net (LGPL)
> 
>> An interesting point about jGraph is that it exports to GXL (Graph 
>> Exchange Language) http://www.gupro.de/GXL/
> 
> I hadn't realised that...interesting!
> 
>> Which brings to mind an interesting set of issues.
>>
>> For instance: the world seems to be awash in ontology expression 
>> languages, like DAML+OIL, OWL (just getting started), CG, RDF, XTM, 
>> and so forth (assuming you'll allow me to group XTM into that cluster).
>>
>> One wonders if the persistence layer of any knowledge product ought 
>> not to consist of something a bit more "universal" (whatever that 
>> means) than XTM.  GXL comes to mind, and Murray Altheim seems to be 
>> heading in that direction. It may be that the GooseWorks package is 
>> going in that direction as well, but I'm not sure yet.
>>
>> This would imply that the next generation of TM4J could be a 
>> wrapper/mapper for a GXL backside.  From the same backside, we could 
>> wrap/map to Conceptual Graphs, DAML+OIL, OWL, and who knows what else.
> 
> That sounds like an interesting approach - in a way it is somewhat 
> similar to what the DOM backend is intending to do - take some standard 
> representation form with a standard API (in this case XTM in the DOM) 
> and add the necessary processing layer to expose that as a topic map 
> with TM4J APIs to it. I have toyed with the idea of a generic node-arc 
> back-end for TM4J, but have decided recently to focus more on building 
> up the front-end (with client apps, web-app frameworks, higher-level 
> utilities, query languages and so on).


I had a minor competition with Peter Becker last fall in developing an
XML serialization of CGs, but have somewhat abandoned that after John
Sowa took all of the development efforts back into the ANSI committee.
I instead decided to look at how GXL could be used for this purpose,
and that's when the light bulb went off -- it was an obvious choice for
a common syntax. I've also written a TG-to-GXL converter in the process,
then realized I wanted a more generalized approach.

 
>> Your thoughts on the notion of going in the direction of a universal, 
>> graph-theoretic backside with wrapper/mappers?
> 
> I think that there shouldn't be anything in the current TM4J back-end 
> architecture that should prevent this from happening and I also think 
> that it could be a very interesting thing to do. If it turns out that 
> something in the way TM4J's backend architecture works prevents this 
> from being possible then we should change that. To be honest, right now 
> my focus is not on creating new backends, but I would certainly support 
> anyone who wants to give it a go!


A little healthy competition is a good thing I think, especially
among friends. I'm hoping over the next few months to hitch up my
TG toolkit to my Xindice DB so that Very Large Graphs (>100K nodes)
can be displayed via locality (ie., n nodes from a selected node).
I once for an experiment tried opening one of my ITIS topic maps
and it took my machine down. Well, not completely, but you get the
picture.

Murray

......................................................................
Murray Altheim                         <mailto:m.altheim @ open.ac.uk>
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK

      In the evening
      The rice leaves in the garden
      Rustle in the autumn wind
      That blows through my reed hut.  -- Minamoto no Tsunenobu