CODEWITHSUNDEEP
scalaapache-sparkspark-graphx
Al Jenssen
Al Jenssen

Reputation: 695

How can I get the number of common edges in Spark Graphx?

For example, if I have two graphs with vertices and edges like this:

import org.apache.spark.graphx._
import org.apache.spark.rdd.RDD

val vertexRdd1: RDD[(VertexId, (String, Int))] = sc.parallelize(Array(
      (1L, ("a", 28)),
      (2L, ("b", 27)),
      (3L, ("c", 65))
))

val edgeRdd1: RDD[Edge[Int]] = sc.parallelize(Array(
    Edge(1L, 2L, 1),
    Edge(2L, 3L, 8)
))

val vertexRdd2: RDD[(VertexId, (String, Int))] = sc.parallelize(Array(
    (1L, ("a", 28)),
    (2L, ("b", 27)),
    (3L, ("c", 28)),
    (4L, ("d", 27)),
    (5L, ("e", 65))
))

val edgeRdd2: RDD[Edge[Int]]  = sc.parallelize(Array(
    Edge(1L, 2L, 1),
    Edge(2L, 3L, 4),
    Edge(3L, 5L, 1),
    Edge(2L, 4L, 1)
))

How can I get the number of common edges between these two graphs, without considering the edge attribute? So, in the above example the number of common edges is 2 and the common edges are: Edge(1L, 2L, 1) common with Edge(1L, 2L, 1) and Edge(2L, 3L, 8) common with Edge(2L, 3L, 4).

I am programming in scala.

Upvotes: 1

Views: 1224

Answers (1)

zero323
zero323

Reputation: 330163

Assuming you have graph1 (Graph(vertexRdd1, edgeRdd1)) and graph2 (Graph(vertexRdd2, edgeRdd2))) you can map edges to (srcId, dstId) and then use intersection method:

val srcDst1 = graph1.edges.map(e => (e.srcId, e.dstId))
val srcDst2 = graph2.edges.map(e => (e.srcId, e.dstId))
srcDst1.intersection(srcDst2).count()

Upvotes: 1

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