diff --git a/examples/src/main/scala/spark/examples/SparkPageRank.scala b/examples/src/main/scala/spark/examples/SparkPageRank.scala index 6d2be34956..4e41c026a4 100644 --- a/examples/src/main/scala/spark/examples/SparkPageRank.scala +++ b/examples/src/main/scala/spark/examples/SparkPageRank.scala @@ -14,7 +14,6 @@ import spark.SparkContext * where URL and their neighbors are separated by space(s). */ object SparkPageRank { - def main(args: Array[String]) { if (args.length < 3) { System.err.println("Usage: PageRank ") @@ -23,22 +22,22 @@ object SparkPageRank { var iters = args(2).toInt val ctx = new SparkContext(args(0), "PageRank", System.getenv("SPARK_HOME"), Seq(System.getenv("SPARK_EXAMPLES_JAR"))) val lines = ctx.textFile(args(1), 1) - val links = lines.map(s => { - val parts = s.split("\\s+") - (parts(0), parts(1)) - }).distinct().groupByKey().cache() + val links = lines.map{s => + val parts = s.split("\\s+") + (parts(0), parts(1)) + }.distinct().groupByKey().cache() var ranks = links.mapValues(v => 1.0) for (i <- 1 to iters) { - val contribs = links.join(ranks).values.flatMap{ case (urls, rank) => { + val contribs = links.join(ranks).values.flatMap{ case (urls, rank) => val size = urls.size urls.map(url => (url, rank / size)) - }} + } - ranks = contribs.groupByKey().mapValues(ranks => { + ranks = contribs.groupByKey().mapValues{ranks => val sumRanks = ranks.foldLeft(0.0)(_ + _) 0.15 + sumRanks * 0.85 - }) + } } val output = ranks.collect()