Yeah, I think I should do it myself. The case for knn seems more
challenging ...
Thanks,
Alireza
On Wednesday, August 12, 2015 at 9:25:52 PM UTC+2, Craig Taverner wrote:
>
> Hi Alireza,
>
> Having two layers is no problem, if you don't mind making and using two.
> It could even be faster to query, because the indexes will be smaller.
>
> You should certainly try the alternative methods for searching for
> neighbours, either the one that takes a suggested limit of results to
> return, or the one where you provide your own search envelope. Each will
> work a little different from the others, and you may find one works best
> for you.
>
> If you know your domain best, you might find that building your own search
> window is the best because you will know things the code cannot.
>
> Regards, Craig
>
> On Wed, Aug 12, 2015 at 5:32 PM, Alireza Rezaei Mahdiraji <
> alire...@gmail.com <javascript:>> wrote:
>
>
> Very well explained, thanks,
>
> However, one problem with one layer solution is that when I am trying Q2
> and Q3 it
> returns also non-point nodes (edge and polygons) which are not part of the
> result.
> So I think it might be better for me to have two layers. Is there any
> performance cost on having several layers?
>
> Using the two layer approach for query Q2 and Q3 I am not getting the
> desired results. For instance for query Q2:
>
> Node s = dbInstance.findNode(dbLabel, "cid", Integer.parseInt(cellId));
> Geometry geometry = layer.getGeometryEncoder().decodeGeometry(s);
>
> List<SpatialDatabaseRecord> snodes = GeoPipeline.
> startNearestNeighborLatLonSearch(layer, geometry.getCoordinate(),
> 1.0).toSpatialDatabaseRecordList();
>
> where the coordinates of node s are (0.0, 0.0). It returns only the node
> itself. Looking at the source,
> it seems startNearestNeighborLatLonSearch builds a window which is much
> more smaller. Should I
> build my own window and pass to startNearestNeighborLatLonSearch instead
> of last param ?
>
> Similar problem with startNearestNeighborSearch when looking for K
> neighbors.
>
> Cheers,
> Thanks,
> Alireza
>
>
>
>
>
> On Wednesday, August 12, 2015 at 4:36:35 PM UTC+2, Craig Taverner wrote:
>
> Hi Alireza,
>
> Since you have three different geometry types, you are correct to use WKT
> (or WKB) for the layer. This layer can handle all three types. You do not
> need a separate layer for points. The only reason I suggested making a
> points-only layer was that I thought perhaps you only stored points. But
> since you store all types, rather have a layer that can handle all.
>
> The code you have above looks fine and similar to the test code I made. So
> it should work fine. The error you had earlier looked like you had tried to
> manually create node geometries and add the nodes to the layer, instead of
> adding the geometry to the layer.
>
> One thing I find a little strange above is that you have chosen to use an
> encoder config with three fields "x:y:z". But the WKB and WKT encoders only
> understand two. The first is the geometry property name (you chose "x" to
> hold the geometry in the node), and the second is the bbox property. I
> think it a little confusing to store a whole polygon in "x" and to store
> the envelope(bbox) in "y". I'm guessing this is not what you intended to
> do? I advise you rather pass a single string with no ':' separators, like
> 'my_geom'. Better yet, leave it empty and get the default value. In fact
> you can leave off all fields but the layer name, if you use the method
> getOrCreateEditableLayer(name).
>
> Here is a section of the test code I tried, which worked, and adds a Point
> and LineString to the layer:
>
> SpatialDatabaseService db = new SpatialDatabaseService( graphDb() );
> String layerName = "myLayer";
> String geomPropertyName = "my_geom";
> EditableLayer layer = (EditableLayer) db.getOrCreateLayer( layerName,
> WKBGeometryEncoder.class,
> EditableLayerImpl.class,
> geomPropertyName );
> GeometryFactory gf = layer.getGeometryFactory();
> SpatialDatabaseRecord record = layer.add( gf.createPoint( new Coordinate(
> 15.25, 56.15 ) ) );
> LinearRing ring = gf.createLinearRing( new Coordinate[]{
> new Coordinate( 15.3, 56.2 ),
> new Coordinate( 15.4, 56.2 ),
> new Coordinate( 15.4, 56.3 ),
> new Coordinate( 15.3, 56.3 ),
> new Coordinate( 15.3, 56.2 )
> } );
> Polygon polygon = gf.createPolygon( ring, null );
> record = layer.add( polygon );
>
> You can use WKB or WKT for this layer. Note that if you created a layer
> with simply:
>
> db.getOrCreateEditableLayer( layerName );
>
> Then you get a WKB layer with default configs.
>
> Regards, Craig
>
>
> On Wed, Aug 12, 2015 at 4:01 PM, Alireza Rezaei Mahdiraji <
> alire...@gmail.com> wrote:
>
>
> Hi Craig,
>
> As always thanks for your nice reply.
>
> I understood the problem but not the solution yet. The fact is I have
> points, lines, and polygons as geometries.
> Four main queries which I have are as follows:
>
> 1- given coordinates of an arbitrary point (i.e., not a node in the graph)
> find the polygon node which enclose it
>
> 2- given a point node find all other nodes which are withing distance r of
> it.
>
> 3- given a point node find all k nearest neighbors point node of it
>
> 4- given two polygon determines if they intersect and perhaps find the
> size of intersection
>
> I defined my layer as follows (I tried with WKB too):
>
> EditableLayer runningLayer = (EditableLayer)
> graphDBSpatial.getOrCreateLayer(layerName,
> WKTGeometryEncoder.class,
> EditableLayerImpl.class,
> "x:y:z");
>
> Then I create my nodes as follows:
>
> // point node
> Point p = runningLayer.getGeometryFactory().createPoint(coord);
> SpatialDatabaseRecord v = runningLayer.add(p);
>
> // edge node
> LineString lineString =
> runningLayer.getGeometryFactory().createLineString(coord);
> SpatialDatabaseRecord e = runningLayer.add(lineString);
>
> // polygon node
> Polygon poly =
> runningLayer.getGeometryFactory().createPolygon(coordinates);
> SpatialDatabaseRecord tc = runningLayer.add(poly);
>
> Based on what you said I should have a separate layer for point, right? If
> the answer is yes, then while querying I should load two layers
> based on which of the queries above is requested (WKT layer for queries 1
> and 4 and Point layer for 2 and 3), is that correct ?
>
> Cheers,
> Alireza
>
> On Monday, August 10, 2015 at 11:09:21 AM UTC+2, Craig Taverner wrote:
>
> Hi Alireza,
>
> I wrote some test code using your layer creation and neighbour search code
> that you pasted, and it works fine. So what I think has happened is that
> you have somehow added nodes with a different layer config to the same
> index that you are now using for WKB. Perhaps the nodes used to be points
> in a simple point layer, and now you changed to a WKB layer, it is no
> longer compatible.
>
> I can make a few suggestions:
>
> - Make sure your nodes were added using the layer.add(Geometry)
> method. If you used layer.add(Node) then it is your responsibility to make
> sure the node conforms to the same layer config that you are planning to
> use. For example, do not add a simple point node (with lat/lon attributes)
> to a WKT layer, or you are likely to create this kind of issue.
> - Since you are working with points, can I suggest you not use the WKB
> layer config, but rather use the SimplePointLayer, as created by
> SpatialGraphDatabase.createSimplePointLayer(name)
> or SpatialGraphDatabase.createSimplePointLayer(name,xProp,yProp)
>
> Regards, Craig
>
> On Sun, Aug 9, 2015 at 12:02 AM, Alireza Rezaei Mahdiraji <
> alire...@gmail.com> wrote:
>
>
> Let me ask you a design kind of question: the nodes in my graph could have
> various geometry: point, line, or polygon.
> I used the following layer definition (but I am not sure that is the best
> way to do it)"
>
> EditableLayer runningLayer = (EditableLayer)
> graphDBSpatial.getOrCreateLayer(layerName,
> WKBGeometryEncoder.class,
> EditableLayerImpl.class,
> geomEncoderConfig);
>
> I appreciate if you comment on this.
>
> Alireza
>
>
> On Saturday, August 8, 2015 at 11:48:24 PM UTC+2, Michael Hunger wrote:
>
> It seems you created the layer with a WKB (well known binary)
> representation config
>
> but now your location properties are not decodable as WKB because they are
> double's ?
>
> Michael
>
> Perhaps you can share a test that reproduces the issue?
>
> Am 08.08.2015 um 23:26 schrieb Alireza Rezaei Mahdiraji <
> alire...@gmail.com>:
>
>
> Here are the stacks for the two cases (very similar):
>
> Exception in thread "main" java.lang.ClassCastException: java.lang.Double
> cannot be cast to [B
> at
> org.neo4j.gis.spatial.WKBGeometryEncoder.decodeGeometry(WKBGeometryEncoder.java:41)
> at
> org.neo4j.gis.spatial.filter.SearchIntersectWindow.onEnvelopeIntersection(SearchIntersectWindow.java:48)
> at
> org.neo4j.gis.spatial.rtree.filter.AbstractSearchEnvelopeIntersection.geometryMatches(AbstractSearchEnvelopeIntersection.java:45)
> at
> org.neo4j.gis.spatial.rtree.RTreeIndex$SearchEvaluator.checkPosition(RTreeIndex.java:286)
> at
> org.neo4j.gis.spatial.rtree.RTreeIndex$SearchEvaluator.isStopNode(RTreeIndex.java:299)
> at
> org.neo4j.kernel.impl.traversal.OldTraverserWrapper$Pruner.evaluate(OldTraverserWrapper.java:260)
> at
> org.neo4j.graphdb.traversal.Evaluator$AsPathEvaluator.evaluate(Evaluator.java:69)
> at
> org.neo4j.kernel.impl.traversal.MultiEvaluator.evaluate(MultiEvaluator.java:62)
> at
> org.neo4j.kernel.impl.traversal.MonoDirectionalTraverserIterator.evaluate(MonoDirectionalTraverserIterator.java:61)
> at
> org.neo4j.kernel.impl.traversal.TraversalBranchImpl.evaluate(TraversalBranchImpl.java:125)
> at
> org.neo4j.kernel.impl.traversal.TraversalBranchImpl.initialize(TraversalBranchImpl.java:130)
> at
> org.neo4j.kernel.impl.traversal.TraversalBranchImpl.next(TraversalBranchImpl.java:151)
> at
> org.neo4j.kernel.impl.traversal.TraversalBranchWithState.next(TraversalBranchWithState.java:32)
> at
> org.neo4j.kernel.impl.traversal.StartNodeTraversalBranch.next(StartNodeTraversalBranch.java:50)
> at
> org.neo4j.graphdb.traversal.PreorderDepthFirstSelector.next(PreorderDepthFirstSelector.java:49)
> at
> org.neo4j.kernel.impl.traversal.MonoDirectionalTraverserIterator.fetchNextOrNull(MonoDirectionalTraverserIterator.java:70)
> at
> org.neo4j.kernel.impl.traversal.MonoDirectionalTraverserIterator.fetchNextOrNull(MonoDirectionalTraverserIterator.java:36)
> at
> org.neo4j.helpers.collection.PrefetchingIterator.peek(PrefetchingIterator.java:60)
> at
> org.neo4j.helpers.collection.PrefetchingIterator.hasNext(PrefetchingIterator.java:46)
> at
> org.neo4j.helpers.collection.PrefetchingIterator.next(PrefetchingIterator.java:75)
> at
> org.neo4j.kernel.impl.traversal.OldTraverserWrapper$TraverserImpl.next(OldTraverserWrapper.java:86)
> at
> org.neo4j.kernel.impl.traversal.OldTraverserWrapper$TraverserImpl.next(OldTraverserWrapper.java:47)
> at
> org.neo4j.gis.spatial.filter.SearchRecords.next(SearchRecords.java:53)
> at
> org.neo4j.gis.spatial.filter.SearchRecords.next(SearchRecords.java:29)
> at org.neo4j.gis.spatial.pipes.GeoPipeline$1.next(GeoPipeline.java:134)
> at org.neo4j.gis.spatial.pipes.GeoPipeline$1.next(GeoPipeline.java:126)
> at
> org.neo4j.gis.spatial.pipes.impl.LastElementIterator.next(LastElementIterator.java:19)
> at
> org.neo4j.gis.spatial.pipes.impl.IdentityPipe.processNextStart(IdentityPipe.java:18)
> at
> org.neo4j.gis.spatial.pipes.impl.AbstractPipe.next(AbstractPipe.java:72)
> at
> org.neo4j.gis.spatial.pipes.AbstractGeoPipe.processNextStart(AbstractGeoPipe.java:49)
> at
> org.neo4j.gis.spatial.pipes.AbstractGeoPipe.processNextStart(AbstractGeoPipe.java:31)
> at
> org.neo4j.gis.spatial.pipes.impl.AbstractPipe.next(AbstractPipe.java:72)
> at org.neo4j.gis.spatial.pipes.impl.Pipeline.next(Pipeline.java:113)
> at
> org.neo4j.gis.spatial.pipes.GeoPipeline.toNodeList(GeoPipeline.java:1015)
>
>
> Exception in thread "main" java.lang.ClassCastException: java.lang.Double
> cannot be cast to [B
> at
> org.neo4j.gis.spatial.WKBGeometryEncoder.decodeGeometry(WKBGeometryEncoder.java:41)
> at
> org.neo4j.gis.spatial.filter.SearchIntersectWindow.onEnvelopeIntersection(SearchIntersectWindow.java:48)
> at
> org.neo4j.gis.spatial.rtree.filter.AbstractSearchEnvelopeIntersection.geometryMatches(AbstractSearchEnvelopeIntersection.java:45)
> at
> org.neo4j.gis.spatial.rtree.RTreeIndex$SearchEvaluator.checkPosition(RTreeIndex.java:286)
> at
> org.neo4j.gis.spatial.rtree.RTreeIndex$SearchEvaluator.isStopNode(RTreeIndex.java:299)
> at
> org.neo4j.kernel.impl.traversal.OldTraverserWrapper$Pruner.evaluate(OldTraverserWrapper.java:260)
> at
> org.neo4j.graphdb.traversal.Evaluator$AsPathEvaluator.evaluate(Evaluator.java:69)
>
> ...
--
You received this message because you are subscribed to the Google Groups
"Neo4j" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to neo4j+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
