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author | Ankur Dave <ankurdave@gmail.com> | 2014-01-12 16:58:18 -0800 |
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committer | Ankur Dave <ankurdave@gmail.com> | 2014-01-12 16:58:18 -0800 |
commit | 7a4bb863c7c11e22332763081793e4989af8c526 (patch) | |
tree | f61fc5e6b144e9c5d5a7415c2a13386089afcded /docs | |
parent | 5e35d39e0f26db3b669bc2318bd7b3f9f6c5fc50 (diff) | |
download | spark-7a4bb863c7c11e22332763081793e4989af8c526.tar.gz spark-7a4bb863c7c11e22332763081793e4989af8c526.tar.bz2 spark-7a4bb863c7c11e22332763081793e4989af8c526.zip |
Add connected components example to doc
Diffstat (limited to 'docs')
-rw-r--r-- | docs/graphx-programming-guide.md | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/docs/graphx-programming-guide.md b/docs/graphx-programming-guide.md index 52668b07c8..22feccb7ad 100644 --- a/docs/graphx-programming-guide.md +++ b/docs/graphx-programming-guide.md @@ -475,6 +475,7 @@ GraphX includes a set of graph algorithms in to simplify analytics. The algorith [Algorithms]: api/graphx/index.html#org.apache.spark.graphx.lib.Algorithms ## PageRank +<a name="pagerank"></a> PageRank measures the importance of each vertex in a graph, assuming an edge from *u* to *v* represents an endorsement of *v*'s importance by *u*. For example, if a Twitter user is followed by many others, the user will be ranked highly. @@ -503,9 +504,26 @@ val ranksByUsername = users.leftOuterJoin(ranks).map { println(ranksByUsername.collect().mkString("\n")) {% endhighlight %} - ## Connected Components +The connected components algorithm labels each connected component of the graph with the ID of its lowest-numbered vertex. For example, in a social network, connected components can approximate clusters. We can compute the connected components of the example social network dataset from the [PageRank section](#pagerank) as follows: + +{% highlight scala %} +// Load the implicit conversion and graph as in the PageRank example +import org.apache.spark.graphx.lib._ +val users = ... +val followers = ... +val graph = Graph(users, followers) +// Find the connected components +val cc = graph.connectedComponents().vertices +// Join the connected components with the usernames +val ccByUsername = graph.vertices.innerJoin(cc) { (id, username, cc) => + (username, cc) +} +// Print the result +println(ccByUsername.collect().mkString("\n")) +{% endhighlight %} + ## Shortest Path ## Triangle Counting |