On Wed, Sep 4, 2013 at 10:59 AM, Dmitriy Lyubimov <dlie...@gmail.com> wrote:
> > Now, what happens in the case of SVD? > > The vectors are normal by definition. > > Are singular values used at all, or just left and right singular vectors? > > SVD does not take weights so it cannot ignore or weigh out a > non-observation, which is why it is not well suited for matrix > completion problem per se > There are multiple ways to read the use of weights here. In the original posting, I think the gist was how to treat the singular values, not how to weight different observations. Mahout's SSVD allows the singular values to be kept separate, to be applied entirely to the left or right singular values or to be split across both in a square root sort of way.
