Returns an RDD that contains for each vertex v its local edges, i.
Returns an RDD that contains for each vertex v its local edges, i.e., the edges that are incident on v, in the user-specified direction. Warning: note that singleton vertices, those with no edges in the given direction will not be part of the return value.
the direction along which to collect the local edges of vertices
the local edges for each vertex
This function could be highly inefficient on power-law graphs where high degree vertices may force a large amount of information to be collected to a single location.
Collect the neighbor vertex ids for each vertex.
Collect the neighbor vertex ids for each vertex.
the direction along which to collect neighboring vertices
the set of neighboring ids for each vertex
Collect the neighbor vertex attributes for each vertex.
Collect the neighbor vertex attributes for each vertex.
the direction along which to collect neighboring vertices
the vertex set of neighboring vertex attributes for each vertex
This function could be highly inefficient on power-law graphs where high degree vertices may force a large ammount of information to be collected to a single location.
Compute the connected component membership of each vertex and return a graph with the vertex value containing the lowest vertex id in the connected component containing that vertex.
Compute the connected component membership of each vertex and return a graph with the vertex value containing the lowest vertex id in the connected component containing that vertex.
The degree of each vertex in the graph.
The degree of each vertex in the graph.
Vertices with no edges are not returned in the resulting RDD.
Filter the graph by computing some values to filter on, and applying the predicates.
Filter the graph by computing some values to filter on, and applying the predicates.
vertex type the vpred operates on
edge type the epred operates on
a function to compute new vertex and edge data before filtering
edge pred to filter on after preprocess, see more details under org.apache.spark.graphx.Graph#subgraph
vertex pred to filter on after prerocess, see more details under org.apache.spark.graphx.Graph#subgraph
a subgraph of the orginal graph, with its data unchanged
This function can be used to filter the graph based on some property, without changing the vertex and edge values in your program. For example, we could remove the vertices in a graph with 0 outdegree
graph.filter( graph => { val degrees: VertexRDD[Int] = graph.outDegrees graph.outerJoinVertices(degrees) {(vid, data, deg) => deg.getOrElse(0)} }, vpred = (vid: VertexId, deg:Int) => deg > 0 )
The in-degree of each vertex in the graph.
The in-degree of each vertex in the graph.
Vertices with no in-edges are not returned in the resulting RDD.
Join the vertices with an RDD and then apply a function from the the vertex and RDD entry to a new vertex value.
Join the vertices with an RDD and then apply a function from the the vertex and RDD entry to a new vertex value. The input table should contain at most one entry for each vertex. If no entry is provided the map function is skipped and the old value is used.
the type of entry in the table of updates
the table to join with the vertices in the graph. The table should contain at most one entry for each vertex.
the function used to compute the new vertex values. The map function is invoked only for vertices with a corresponding entry in the table otherwise the old vertex value is used.
This function is used to update the vertices with new values based on external data. For example we could add the out degree to each vertex record
val rawGraph: Graph[Int, Int] = GraphLoader.edgeListFile(sc, "webgraph") .mapVertices(v => 0) val outDeg: RDD[(Int, Int)] = rawGraph.outDegrees val graph = rawGraph.leftJoinVertices[Int,Int](outDeg, (v, deg) => deg )
The number of edges in the graph.
The number of vertices in the graph.
The out-degree of each vertex in the graph.
The out-degree of each vertex in the graph.
Vertices with no out-edges are not returned in the resulting RDD.
Run a dynamic version of PageRank returning a graph with vertex attributes containing the PageRank and edge attributes containing the normalized edge weight.
Run a dynamic version of PageRank returning a graph with vertex attributes containing the PageRank and edge attributes containing the normalized edge weight.
Picks a random vertex from the graph and returns its ID.
Execute a Pregel-like iterative vertex-parallel abstraction.
Execute a Pregel-like iterative vertex-parallel abstraction. The
user-defined vertex-program vprog
is executed in parallel on
each vertex receiving any inbound messages and computing a new
value for the vertex. The sendMsg
function is then invoked on
all out-edges and is used to compute an optional message to the
destination vertex. The mergeMsg
function is a commutative
associative function used to combine messages destined to the
same vertex.
On the first iteration all vertices receive the initialMsg
and
on subsequent iterations if a vertex does not receive a message
then the vertex-program is not invoked.
This function iterates until there are no remaining messages, or
for maxIterations
iterations.
the Pregel message type
the message each vertex will receive at the on the first iteration
the maximum number of iterations to run for
the direction of edges incident to a vertex that received a message in
the previous round on which to run sendMsg
. For example, if this is EdgeDirection.Out
, only
out-edges of vertices that received a message in the previous round will run.
the user-defined vertex program which runs on each vertex and receives the inbound message and computes a new vertex value. On the first iteration the vertex program is invoked on all vertices and is passed the default message. On subsequent iterations the vertex program is only invoked on those vertices that receive messages.
a user supplied function that is applied to out edges of vertices that received messages in the current iteration
a user supplied function that takes two incoming messages of type A and merges them into a single message of type A. This function must be commutative and associative and ideally the size of A should not increase.
the resulting graph at the end of the computation
Run PageRank for a fixed number of iterations returning a graph with vertex attributes containing the PageRank and edge attributes the normalized edge weight.
Run PageRank for a fixed number of iterations returning a graph with vertex attributes containing the PageRank and edge attributes the normalized edge weight.
Compute the strongly connected component (SCC) of each vertex and return a graph with the vertex value containing the lowest vertex id in the SCC containing that vertex.
Compute the strongly connected component (SCC) of each vertex and return a graph with the vertex value containing the lowest vertex id in the SCC containing that vertex.
Compute the number of triangles passing through each vertex.
Compute the number of triangles passing through each vertex.
Contains additional functionality for Graph. All operations are expressed in terms of the efficient GraphX API. This class is implicitly constructed for each Graph object.
the vertex attribute type
the edge attribute type