From 46b195253ecb54ff8a202a53773fc9388b2c753c Mon Sep 17 00:00:00 2001
From: "Joseph E. Gonzalez" <joseph.e.gonzalez@gmail.com>
Date: Tue, 22 Oct 2013 15:01:49 -0700
Subject: [PATCH] Adding some additional graph generators to support unit
testing of the analytics package.
---
.../spark/graph/util/GraphGenerators.scala | 46 ++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/graph/src/main/scala/org/apache/spark/graph/util/GraphGenerators.scala b/graph/src/main/scala/org/apache/spark/graph/util/GraphGenerators.scala
index 895c65c14c..1bbcce5039 100644
--- a/graph/src/main/scala/org/apache/spark/graph/util/GraphGenerators.scala
+++ b/graph/src/main/scala/org/apache/spark/graph/util/GraphGenerators.scala
@@ -236,7 +236,51 @@ object GraphGenerators {
}
}
-}
+
+
+ /**
+ * Create `rows` by `cols` grid graph with each vertex connected to its
+ * row+1 and col+1 neighbors. Vertex ids are assigned in row major
+ * order.
+ *
+ * @param sc the spark context in which to construct the graph
+ * @param rows the number of rows
+ * @param cols the number of columns
+ *
+ * @return A graph containing vertices with the row and column ids
+ * as their attributes and edge values as 1.0.
+ */
+ def gridGraph(sc: SparkContext, rows: Int, cols: Int): Graph[(Int,Int), Double] = {
+ // Convert row column address into vertex ids (row major order)
+ def sub2ind(r: Int, c: Int): Vid = r * cols + c
+
+ val vertices: RDD[(Vid, (Int,Int))] =
+ sc.parallelize(0 until rows).flatMap( r => (0 until cols).map( c => (sub2ind(r,c), (r,c)) ) )
+ val edges: RDD[Edge[Double]] =
+ vertices.flatMap{ case (vid, (r,c)) =>
+ (if (r+1 < rows) { Seq( (sub2ind(r, c), sub2ind(r+1, c))) } else { Seq.empty }) ++
+ (if (c+1 < cols) { Seq( (sub2ind(r, c), sub2ind(r, c+1))) } else { Seq.empty })
+ }.map{ case (src, dst) => Edge(src, dst, 1.0) }
+ Graph(vertices, edges)
+ } // end of gridGraph
+
+ /**
+ * Create a star graph with vertex 0 being the center.
+ *
+ * @param sc the spark context in which to construct the graph
+ * @param the number of vertices in the star
+ *
+ * @return A star graph containing `nverts` vertices with vertex 0
+ * being the center vertex.
+ */
+ def starGraph(sc: SparkContext, nverts: Int): Graph[Int, Int] = {
+ val edges: RDD[(Vid, Vid)] = sc.parallelize(1 until nverts).map(vid => (vid, 0))
+ Graph(edges, false)
+ } // end of starGraph
+
+
+
+} // end of Graph Generators
--
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