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From Dmitriy Lyubimov <dlie...@gmail.com>
Subject Re: SSVD Wrong Singular Vectors
Date Sat, 01 Sep 2012 05:54:03 GMT
No, that should not be the case unless your input is random and k+p <<
rank(A). However, let me double check what you are saying, maybe something
got broken.
On Aug 31, 2012 10:28 PM, "Ahmed Elgohary" <aagohary@gmail.com> wrote:

> Hi,
>
> I used mahout's stochastic svd implementation to find the singular vectors
> and the singular vectors of a small matrix 99x100. Then, I compared the
> results to the singular values and the singular vectors obtained using the
> svd function in matlab and the single threaded version of the ssvd. I got
> pretty much the same singular values using the 3 implementations. however,
> the singular vectors of mahout's ssvd were significantly different. I tried
> multiple values for the parameters P and Q but, that does not seem to solve
> the problem. Does MR implementation of the SSVD do extra approximations
> over the single threaded ssvd so their results might not be the same? Any
> advice how I can tune mahout's ssvd to get the same singular vectors of the
> single threaded ssvd?
>
> thanks,
>
> --ahmed
>

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