You are viewing a plain text version of this content. The canonical link for it is here.

Posted to issues@commons.apache.org by "Morikawa Joe (JIRA)" <ji...@apache.org> on 2016/02/09 14:13:18 UTC

[jira] [Created] (MATH-1322) Negative integer seed for MersenneTwister is not working.

Morikawa Joe created MATH-1322:
----------------------------------

             Summary: Negative integer seed for MersenneTwister is not working.
                 Key: MATH-1322
                 URL: https://issues.apache.org/jira/browse/MATH-1322
             Project: Commons Math
          Issue Type: Bug
    Affects Versions: 3.6
            Reporter: Morikawa Joe


MersenneTwister.setSeed(int seed) has a bug.

If seed is negative, longMT also becomes negative.
First 32 bits are filled by 0xFFFFFFFF.
But it should be positive. First 32 bits should be filled by 0x00000000.

Ex) Integer -1 is 0xffffffff. 
Long -1 is 0xffffffffffffffff.
Long 0xffffffff is 4294967295.

I created simple patch. 







--
This message was sent by Atlassian JIRA
(v6.3.4#6332)