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https://issues.apache.org/jira/browse/MAHOUT-687?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13037230#comment-13037230
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Lance Norskog commented on MAHOUT-687:
--------------------------------------
bq. Is this still useful? I am like Sean and have lost the thrust of the patch.
I'm still working on it.
Ted, you mentioned wanting a MurmurHash Random class. Is this what you
envisioned? (It is not finished code; see below).
{code}
public class MurmurHashRandom extends Random {
private long murmurSeed;
private final ByteBuffer buf;
public MurmurHashRandom() {
this(0);
}
public MurmurHashRandom(int seed) {
SeedGenerator gen = new FastRandomSeedGenerator();
byte[] bits = RandomUtils.longSeedtoBytes(gen.generateSeed());
buf = ByteBuffer.wrap(bits);
this.murmurSeed = MurmurHash.hash64A(bits, seed);
}
@Override
public long nextLong() {
long oldSeed = murmurSeed;
murmurSeed = MurmurHash.hash64A(buf, (int) murmurSeed);
return oldSeed;
}
{code}
It is coded against my patch, so is only here for study purposes.It's coded
against the MurmurHash class in encoders.encoders.MurmurHash works in ints, not
longs, so types are a bit confused in this demo code.
> Random generator objects- slight refactor
> -----------------------------------------
>
> Key: MAHOUT-687
> URL: https://issues.apache.org/jira/browse/MAHOUT-687
> Project: Mahout
> Issue Type: Improvement
> Reporter: Lance Norskog
> Priority: Minor
> Attachments: MAHOUT-687.patch, MAHOUT-687.patch
>
>
> Problems:
> * The uncommons RepeatableRNG classes are the basis of RandomUtils.
> ** These classes cheerfully ignore setSeed.
> * Some people in the project want to move off Uncommons anyway.
> This patch uses the org.apache.commons.math.random.RandomGenerator classes
> instead of org.apache.uncommons.maths.RepeatableRNG classes.
> .
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