Writing ELKI DBSCAN convex hull of clusters to file -

i have started using elki data analysis, 1 seemingly simple thing cannot seem output calculated convex hull of clusters file after running dbscan. able visualize convex hulls via visualization gui, cannot generate kml file. able write clustering results folder (using resultwriter resulthandler), no file generated when set kmloutputhandler. receive no error message in log window (even verbose parameter set true).

is there trick generating kml file in elki? walk through steps of doing this?

any appreciated.

(as aside, possible generate alpha shapes dbscan results elki? if so, parameter must adjusted?)

so lot of questions in one...

1. cunvex hulls: used in elki visualization, not considered part of output result, not saved file. trick employ save visualization svg , extract them file, in different coordinate system.

   one of reasons convex hulls implemented 2d euclidean space - figure want use spatial data, may happen not return correct convex hull due curvature of earth surface. furthermore, many data sets of higher dimensionality.

   however, can of course @ source code , invoke convex hull algorithm, write result favorite output format. in general, need spend time on preprocessing, need customize output.

2. which brings me second question. kmlresulthandler closely tied publication of elki 0.4.0: spatial outlier detection: data, algorithms, visualizations. pretty summarizes class does: visualize spatial outlier detection. not (yet) include code visualize clusters of spatial data, example. in order output class, need ensure number of restrictions, unfortunately. essentially, if finds polygon relation , outlierresult can map each other, output kml. not yet class write arbitrary results kml. needs lot more of documentation, too. contributions of more general output tool appreciated; customizeable, automatic, general output kml really hard do. in particular, may end having include projection capabilities then, if not processing latitude-longitude data, e.g. utm projected data. such, recommend looking @ source code of class , customizing needs. in opinion, visualization kml require lot of customization.

3. to generate alpha shapes (only hull, not extended alpha shape - optimal visualization of dbscan consist of alpha shape of core points only, extended radius of epsilon, should include border points. on wish list, not implemented), need set -hull.alpha parameter desired alpha value. note happens in visualization projection, not @ raw data. if axes scaled differently, alpha shapes differently. again, may interested in using class alphashape on raw data vectors, instead of exporting projected visualization. can write resulting polygons custom visualization.

if implement such kml visualization using alpha shapes (or convex hulls) clusters, appreciate if contribute elki make available others well. thank you.