You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@commons.apache.org by "Thomas Neidhart (JIRA)" <ji...@apache.org> on 2013/12/01 20:18:35 UTC
[jira] [Commented] (MATH-1068) KendallsCorrelation suffers from
integer overflow for large arrays.
[ https://issues.apache.org/jira/browse/MATH-1068?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13836097#comment-13836097 ]
Thomas Neidhart commented on MATH-1068:
---------------------------------------
Fixed in r1546840.
Thanks for the report!
> KendallsCorrelation suffers from integer overflow for large arrays.
> -------------------------------------------------------------------
>
> Key: MATH-1068
> URL: https://issues.apache.org/jira/browse/MATH-1068
> Project: Commons Math
> Issue Type: Bug
> Affects Versions: 3.3
> Reporter: Gal Lalouche
> Priority: Minor
> Labels: newbie
> Fix For: 3.3
>
> Original Estimate: 1m
> Remaining Estimate: 1m
>
> For large array size (say, over 5,000), numPairs > 10 million.
> in line 258, (numPairs - tiedXPairs) * (numPairs - tiedYPairs) possibly > 100 billion, which will cause an integer overflow, resulting in a negative number, which will result in the end result in a NaN since the square-root of that number is calculated.
> This can easily be solved by changing line 163 to
> final long numPairs = ((long)n) * (n - 1) / 2; // to avoid overflow
--
This message was sent by Atlassian JIRA
(v6.1#6144)