Hi Matthias On Tue, Jun 24, 2014 at 10:07 PM, Matthias Ludwig <[email protected]> wrote: > Hi, > > for a project (python standalone) I try to display points in "clusters" > (like the Leaflet-marker-Cluster > http://leaflet.github.io/Leaflet.markercluster/example/marker-clustering-realworld.388.html, > or Openlayers, etc. just a simple distance based solution). As far as I > understand the PointDisplacementRenderer more or less it does the same: > group all points in a radius into a cluster and show the center point. If > the tolerance is set depending on the scale the center points are displayed > properly. > I looked into the docs and the source code and didn't found a way to access > the list of displacementGroups (to get the count and the center point) or > just the count of points in each group. After that I tried to modify the > source code of the renderer. I made the mDisplacementGroups publicly > accessable (or i tried to do so) and moved the: > typedef QMap<QgsFeatureId, QgsFeature> DisplacementGroup; > /**Groups of features that have the same position*/ > QList<DisplacementGroup> mDisplacementGroups; > /**Mapping from feature ID to its group index*/ > above the private section but it didn't worked. Is this completly wrong or > do I have to change something else to get access with the python bindings? > Is there any way to get the center point of each group and the count from > the current implementation?
Those members variables are just temporary and not meant to be used publicly. I don't think there is a way to retrieve these groupings. > I didn't found something in the mailing list or somewhere else: is someone > working on a "visual clustering" solution? If the time will allow, I would like to do few improvements to the point displacement renderer. It would probably make sense to actually take the clustering out of the renderer and have a class just for the clustering algorithm that will return the groups. Regards Martin _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
