Thanks- I will mess around in R with this advice. On Mon, Sep 17, 2012 at 12:30 AM, Sean Owen <[email protected]> wrote: > On Mon, Sep 17, 2012 at 12:11 AM, Ted Dunning <[email protected]> wrote: > >> A_k = U_k U_k' A_k > >> Forgetting S_k is a bit dangerous here. It is true that >> >> U_k S_k = A_k V_k >> >> But, of course, right multiplying by V_k' gives us the identity above. >> >> I think that the real confusion is that I am talking about projecting back >> into span A and you are talking about expressing things in terms of the >> latent variables. > > Right, this goes all the way to "making recommendations", back to Ak. > I think Lance was asking about how to find the new row in latent > feature space, a row in Uk. > > You can't ignore Sk, yes, just trying to get to the essence. Putting > it back in (half-and-half) does get what I posted which indeed is the > project I think that was in question.. > > Uk * sqrt(Sk) = Ak * Vk * 1/sqrt(Sk)
-- Lance Norskog [email protected]
