I think you will want to look inside the code of both of those; and produce
your own graph generator that does exactly what you want.
Jody
On 17/06/2010, at 5:27 PM, Oleg Demchenko wrote:
> Hi Jody.
>
> I'm using DirectedLineStringGraphGenerator to build a Directed Graph from
> Vector<LineString>.
> ...
>
> //create a linear graph generate
> DirectedLineStringGraphGenerator lineStringGen = new
> DirectedLineStringGraphGenerator();
> for (int i = 0; i < lines.size(); ++i) {
> lineStringGen.add((LineString) lines.get(i));
> }
> DirectedGraph g= lineStringGen.getGraph();
>
> Also there is example from GEOTools documentation which use
> FeatureGraphGenerator wrapper
> // get a feature collection somehow
> FeatureCollection fCollection = featureSource.getFeatures(Filter.INCLUDE);
> FeatureIterator featureIterator = fCollection.features();
>
> //create a linear graph generate
> LineStringGraphGenerator lineStringGen = new LineStringGraphGenerator();
> //wrap it in a feature graph generator
> FeatureGraphGenerator featureGen = new FeatureGraphGenerator( lineStringGen );
> //throw all the features into the graph generator
> Iterator iter = fCollection.iterator();
> while(iter.hasNext()){
> Feature feature = (Feature)iter.next();
> featureGen.add( feature );
> }
> Graph g = featureGen.getGraph()
>
> Please, advice what is class name of the builder which may help me to build a
> well connected graph from a line segments?
>
>
> 2010/6/17 Jody Garnett <jody.garn...@gmail.com>
> There is also a seperate builder that builds a graph based on the line
> segmenets; perhaps you could combine the two ideas in your own graph builder
> and contribute the result back/
>
> Jody
>
> On 16/06/2010, at 8:08 PM, Oleg Demchenko wrote:
>
>> Hi Dear All.
>>
>> I'm quite new in Geotools area and hope somebody of you will point me a
>> proper direction.
>>
>> I'm developing a server side Java method which should estimate shortest
>> vehicle path between any 2 points placed within 1 country.
>>
>> Data is given from a Denmark OSM highway shapefile downloaded from public
>> CloudsMade server. In order to optimize process I'm selecting from database
>> features (lines) placed within a rectangle between start and end points.
>> Usually it is 1500- 10 000 of LineString objects.
>>
>> From geotools-gt2-users mail archive I've learnt that lines MUST be
>> intersected each other otherwise DijkstraShortestPathFinder will not return
>> any path between given source and destination nodes for a Directed graph
>> built from a lines array.
>> There is mailing initiated by Cris
>> (http://www.mail-archive.com/geotools-gt2-users@lists.sourceforge.net/msg04520.html)
>> regarding splitlines function. I'm using last function version published by
>> Cris Jan 2008 (please find it at the end of the mail), but after days of
>> debug found it over optimized.
>>
>> Usually it is only double number of lines from input Vector<LineString>. For
>> 1500 lines it built less then 3000 of intersected lines. As an Impact
>> DijkstraShortestPathFinder can't find a path for the most source/destination
>> points distanced more then 40 Kms each other, because Graph is not well
>> connected.
>>
>> Could somebody point me, please, on the source where I could find good
>> intersection method for Vector<LineString> using Quadtree?
>>
>> How I can check that Graph is well partitioned and most of nodes are
>> connected each other?
>>
>> Thank you in advance for your reply.
>
>
> --
> All the best
> Oleg Demchenko
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