Andrew Ray 78062b8521 [SPARK-18845][GRAPHX] PageRank has incorrect initialization value that leads to slow convergence ... ## What changes were proposed in this pull request? Change the initial value in all PageRank implementations to be `1.0` instead of `resetProb` (default `0.15`) and use `outerJoinVertices` instead of `joinVertices` so that source vertices get updated in each iteration. This seems to have been introduced a long time ago in 15a564598f (diff-b2bf3f97dcd2f19d61c921836159cda9L90) With the exception of graphs with sinks (which currently give incorrect results see SPARK-18847) this gives faster convergence as the sum of ranks is already correct (sum of ranks should be number of vertices). Convergence comparision benchmark for small graph: http://imgur.com/a/HkkZf Code for benchmark: https://gist.github.com/aray/a7de1f3801a810f8b1fa00c271a1fefd ## How was this patch tested? (corrected) existing unit tests and additional test that verifies against result of igraph and NetworkX on a loop with a source. Author: Andrew Ray <ray.andrew@gmail.com> Closes #16271 from aray/pagerank-initial-value.		2016-12-15 23:32:10 -08:00
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src	[SPARK-18845][GRAPHX] PageRank has incorrect initialization value that leads to slow convergence	2016-12-15 23:32:10 -08:00
pom.xml	[SPARK-18695] Bump master branch version to 2.2.0-SNAPSHOT	2016-12-02 21:09:37 -08:00