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https://issues.apache.org/jira/browse/MATH-1300?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15065149#comment-15065149
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Rostislav Krasny edited comment on MATH-1300 at 12/19/15 2:03 AM:
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Attaching the code.
New BitsStreamGenerator#nextBytes(byte[]) implementation, made as an overriden
method of MersenneTwister. Copy this nextBytes(byte[]) implementation into the
BitsStreamGenerator code.
The second file is a Unit test that demonstrates the wrong and the right
nextBytes(byte[]) behaviors.
was (Author: rosti.bsd):
New BitsStreamGenerator#nextBytes(byte[]) implementation, made as an overriden
method of MersenneTwister. Copy this nextBytes(byte[]) implementation into the
BitsStreamGenerator code.
The second file is a Unit test that demonstrates the wrong and the right
nextBytes(byte[]) behaviors.
> BitsStreamGenerator#nextBytes(byte[]) is wrong
> ----------------------------------------------
>
> Key: MATH-1300
> URL: https://issues.apache.org/jira/browse/MATH-1300
> Project: Commons Math
> Issue Type: Bug
> Affects Versions: 3.5
> Reporter: Rostislav Krasny
> Attachments: MersenneTwister2.java, TestMersenneTwister.java
>
>
> Sequential calls to the BitsStreamGenerator#nextBytes(byte[]) must generate
> the same sequence of bytes, no matter by chunks of which size it was divided.
> This is also how java.util.Random#nextBytes(byte[]) works.
> When nextBytes(byte[]) is called with a bytes array of length multiple of 4
> it makes one unneeded call to next(int) method. This is wrong and produces an
> inconsistent behavior of classes like MersenneTwister.
> I made a new implementation of the BitsStreamGenerator#nextBytes(byte[]) see
> attached code.
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