Add LabelPropagationSuite

Author: ankurdave

graphx/src/test/scala/org/apache/spark/graphx/lib/LabelPropagationSuite.scala

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.graphx.lib
+
+import org.scalatest.FunSuite
+
+import org.apache.spark.graphx._
+
+class LabelPropagationSuite extends FunSuite with LocalSparkContext {
+  test("Label Propagation") {
+    withSpark { sc =>
+      // Construct a graph with two cliques connected by a single edge
+      val n = 5
+      val clique1 = for (u <- 0L until n; v <- 0L until n) yield Edge(u, v, 1)
+      val clique2 = for (u <- 0L to n; v <- 0L to n) yield Edge(u + n, v + n, 1)
+      val twoCliques = sc.parallelize(clique1 ++ clique2 :+ Edge(0L, n, 1))
+      val graph = Graph.fromEdges(twoCliques, 1)
+      // Run label propagation
+      val labels = LabelPropagation.run(graph, n * 4).cache()
+
+      // All vertices within a clique should have the same label
+      val clique1Labels = labels.vertices.filter(_._1 < n).map(_._2).collect.toArray
+      assert(clique1Labels.forall(_ == clique1Labels(0)))
+      val clique2Labels = labels.vertices.filter(_._1 >= n).map(_._2).collect.toArray
+      assert(clique2Labels.forall(_ == clique2Labels(0)))
+      // The two cliques should have different labels
+      assert(clique1Labels(0) != clique2Labels(0))
+    }
+  }
+}