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https://issues.apache.org/jira/browse/SPARK-18845?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15746385#comment-15746385
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Andrew Ray commented on SPARK-18845:
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[~srowen] No that's a different thing just whether the result sums to 1 or n.
But to expand on that, since we are using the version that sums to n our
initial ranks need to sum to n or it takes a lot longer to converge.
> PageRank has incorrect initialization value that leads to slow convergence
> --------------------------------------------------------------------------
>
> Key: SPARK-18845
> URL: https://issues.apache.org/jira/browse/SPARK-18845
> Project: Spark
> Issue Type: Bug
> Components: GraphX
> Affects Versions: 1.2.2, 1.3.1, 1.4.1, 1.5.2, 1.6.3, 2.0.2
> Reporter: Andrew Ray
>
> All variants of PageRank in GraphX have incorrect initialization value that
> leads to slow convergence. In the current implementations ranks are seeded
> with the reset probability when it should be 1. This appears to have been
> introduced a long time ago in
> https://github.com/apache/spark/commit/15a564598fe63003652b1e24527c432080b5976c#diff-b2bf3f97dcd2f19d61c921836159cda9L90
> This also hides the fact that source vertices (vertices with no incoming
> edges) are not updated. This is because source vertices generally* have
> pagerank equal to the reset probability. Therefore both need to be fixed at
> once.
> PR will be added shortly
> *when there are no sinks -- but that's a separate bug
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