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https://issues.apache.org/jira/browse/MATH-1322?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15139141#comment-15139141
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Gilles commented on MATH-1322:
------------------------------
With the code you wrote above:
{code}
MersenneTwister rng = new MersenneTwister();
rng.setSeed((int) -1);
// Without patch, "-931718226" is output.
// After applying patch, "419326371" is output.
System.out.println(rng.nextInt());
{code}
what is the output of
{code}
rng.setSeed((long) -1);
{code}
# in the current code and
# with the patch applied
?
> 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
> Labels: patch
> Attachments: MersenneTwister.patch
>
>
> 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.
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