Hi Trevor, note that the community detection algorithm returns a new graph where the vertex values correspond to the computed communities. Also, note that the current implementation expects a graph with java.lang.Long vertex values and java.lang.Double edge values.
The following should work: import java.lang.Long import java.lang.Double ... val graph: Graph[Long, Long, Double] = ... // create your graph val resultGraph = graph.run(new CommunityDetection[Long](30, 0.5)) resultGraph.getVertices.print() Cheers, -Vasia. On 27 April 2016 at 17:41, Suneel Marthi <smar...@apache.org> wrote: > Recall facing a similar issue while trying to contribute a gelly-scala > example to flink-training. > > See > https://github.com/dataArtisans/flink-training-exercises/blob/master/src/main/scala/com/dataartisans/flinktraining/exercises/gelly_scala/PageRankWithEdgeWeights.scala > > On Wed, Apr 27, 2016 at 11:35 AM, Trevor Grant <trevor.d.gr...@gmail.com> > wrote: > >> The following example in the scala shell worked as expected: >> >> import org.apache.flink.graph.library.LabelPropagation >> >> val verticesWithCommunity = graph.run(new LabelPropagation(30)) >> >> // print the result >> verticesWithCommunity.print >> >> >> I tried to extend the example to use CommunityDetection: >> >> import org.apache.flink.graph.library.CommunityDetection >> >> val verticesWithCommunity = graph.run(new CommunityDetection(30, 0.5)) >> >> // print the result >> verticesWithCommunity.print >> >> >> And meant the following error: >> error: polymorphic expression cannot be instantiated to expected type; >> found : [K]org.apache.flink.graph.library.CommunityDetection[K] >> required: org.apache.flink.graph.GraphAlgorithm[Long,String,Double,?] >> val verticesWithCommunity = graph.run(new CommunityDetection(30, 0.5)) >> ^ >> >> I haven't been able to come up with a hack to make this work. Any >> advice/bug? >> >> I invtestigated the code base a little, seems to be an issue with what >> Graph.run expects to see vs. what LabelPropagation returns vs. what >> CommunityDetection returns. >> >> >> >> Trevor Grant >> Data Scientist >> https://github.com/rawkintrevo >> http://stackexchange.com/users/3002022/rawkintrevo >> http://trevorgrant.org >> >> *"Fortunate is he, who is able to know the causes of things." -Virgil* >> >> >
