Stochastic projection (SSVD) to use 64bit murmur hash to produce uniform
distribution vectors
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Key: MAHOUT-673
URL: https://issues.apache.org/jira/browse/MAHOUT-673
Project: Mahout
Issue Type: Improvement
Affects Versions: 0.4
Reporter: Dmitriy Lyubimov
Assignee: Dmitriy Lyubimov
Priority: Minor
Fix For: 0.6
So, per earlier discussion on the list: for random matrix Omega in stochastic
projection, let's use murmur hash to generate uniformly distributed elements in
a closed interval [-1,+1] instead of using Random.nextGaussian().
I am not sure if there's really compelling mathematical reason to do this but
maybe it's just faster and more inline with practice accepted in Mahout for all
this.
The murmur 64bit value is already in the code. I just need to figure the
optimal way to convert it into a uniform distribution.
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