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https://issues.apache.org/jira/browse/SPARK-7210?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14608976#comment-14608976
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Feynman Liang commented on SPARK-7210:
--------------------------------------

Some relevant links:

[A R cookbook 
recipe|http://thirteen-01.stat.iastate.edu/snoweye/hpsc/?item=cookbook&subitem=ex_mvn]
 describing and implementing mvn densities using Cholesky decomposition.
[Another R reference with the same implementation as 
above|http://gallery.rcpp.org/articles/dmvnorm_arma/]
[The C++ code called by R's `mvnfast` package 
|https://github.com/mfasiolo/mvnfast/blob/master/src/rmvnCpp.cpp]

> Test matrix decompositions for speed vs. numerical stability for Gaussians
> --------------------------------------------------------------------------
>
>                 Key: SPARK-7210
>                 URL: https://issues.apache.org/jira/browse/SPARK-7210
>             Project: Spark
>          Issue Type: Improvement
>          Components: MLlib
>            Reporter: Joseph K. Bradley
>            Priority: Minor
>
> We currently use SVD for inverting the Gaussian's covariance matrix and 
> computing the determinant.  SVD is numerically stable but slow.  We could 
> experiment with Cholesky, etc. to figure out a better option, or a better 
> option for certain settings.



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