Hi Vasia, for compute subgraph for Person I mean exactly all the vertices that can be reached starting from this node and following the graph edges. I drafted the graph as a set of vertices (where the id is the subject of the set of triples and the value is all of its triples) and a set of edges (properties connecting two vertices, this is only possible if the object is an URI).
Thus, once computed the subgraph of a Person, if I merge the values of all reachable vertices, I'll obtain all the triples of such a subgraph. On Tue, Apr 14, 2015 at 4:55 PM, Vasiliki Kalavri <vasilikikala...@gmail.com > wrote: > Hi Flavio, > > I'm not quite familiar with RDF or sparql, so not all of your code is clear > to me. > > Your first TODO is "compute subgraph for Person". Is "Person" a vertex id > in your graph? A vertex value? > And by "subgraph of Person", do you mean all the vertices that can be > reached starting from this node and following the graph edges? > > -Vasia. > > On 14 April 2015 at 10:37, Flavio Pompermaier <pomperma...@okkam.it> > wrote: > > > Hi to all, > > I made a simple RDF Gelly test and I shared it on my github repo at > > https://github.com/fpompermaier/rdf-gelly-test. > > I basically setup the Gelly stuff but I can't proceed and compute the > > drafted TODOs. > > Could someone help me and implementing them..? > > I think this could become a nice example of how Gelly could help in > > handling RDF graphs :) > > > > Best, > > Flavio > > > > On Mon, Mar 23, 2015 at 10:41 AM, Flavio Pompermaier < > pomperma...@okkam.it > > > > > wrote: > > > > > Thanks Vasiliki, > > > when I'll find the time I'll try to make a quick prototype using the > > > pointers you suggested! > > > > > > Thanks for the support, > > > Flavio > > > > > > On Mon, Mar 23, 2015 at 10:31 AM, Vasiliki Kalavri < > > > vasilikikala...@gmail.com> wrote: > > > > > >> Hi Flavio, > > >> > > >> I'm not familiar with JSON-LD, but as far as I understand, you want to > > >> generate some trees from selected root nodes. > > >> > > >> Once you have created the Graph as Andra describes above, you can > first > > >> filter out the edges that are of no interest to you, using > > filterOnEdges. > > >> There is a description of how edge filtering works in the Gelly docs > > [1]. > > >> Then, you could use a vertex-centric iteration and propagate a message > > >> from > > >> the selected root node to the neighbors recursively, until you have > the > > >> tree. > > >> > > >> In the vertex-centric model, you program from the perspective of a > > vertex > > >> in the graph. You basically need to define what each vertex does > within > > >> each iteration (superstep). In Gelly this boils down to two things: > > >> (a) what messages this vertex will send to its neighbors and > > >> (b) how a vertex will update its value using the received messages. > > >> > > >> This is also described in the Gelly docs [2]. > > >> Also, take a look at the Gelly library [3]. The library methods are > > >> implemented using this model and should give you an idea. > > >> > > >> In your case, you will probably need to simply propagate one message > > from > > >> the root node and gather the newly discovered neighbors in each > > superstep. > > >> > > >> I hope this helps! Let us know if you have further questions! > > >> > > >> -Vasia. > > >> > > >> [1]: > > >> > > >> > > > http://ci.apache.org/projects/flink/flink-docs-master/gelly_guide.html#graph-transformations > > >> > > >> [2]: > > >> > > >> > > > http://ci.apache.org/projects/flink/flink-docs-master/gelly_guide.html#vertex-centric-iterations > > >> > > >> [3]: > > >> > > >> > > > http://github.com/apache/flink/tree/master/flink-staging/flink-gelly/src/main/java/orgThehveflink/graph/library > > >> > > > > > > > > > > > >
