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https://issues.apache.org/jira/browse/MATH-1300?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15065489#comment-15065489
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Gilles commented on MATH-1300:
------------------------------
Two runs from me: ;)
{noformat}
nextBytes (calls per timed block: 200000, timed blocks: 100, time unit: ms)
name time/call std error total time ratio difference
Rostislav 2.27207249e-04 5.12523201e-05 4.5441e+03 1.0000e+00 0.00000000e+00
Gilles 2.41729594e-04 3.13763057e-05 4.8346e+03 1.0639e+00 2.90446893e+02
CommonsMath 2.25267632e-04 3.46659491e-05 4.5054e+03 9.9146e-01 -3.87923460e+01
{noformat}
{noformat}
nextBytes (calls per timed block: 200000, timed blocks: 100, time unit: ms)
name time/call std error total time ratio difference
Rostislav 2.32682559e-04 3.84982763e-05 4.6537e+03 1.0000e+00 0.00000000e+00
Gilles 2.49178627e-04 3.92662253e-05 4.9836e+03 1.0709e+00 3.29921360e+02
CommonsMath 2.26983378e-04 2.72215448e-05 4.5397e+03 9.7551e-01 -1.13983632e+02
{noformat}
I'm still ~7% slower than you, but that's far from the ~50% which your
benchmark indicates.
In your benchmark, your code is faster that the current CM code; but in mine,
it's the other way around...
> 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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