In any event i hope you could review stuff going on there. There are problems that need answers.
On Mon, Nov 28, 2011 at 12:50 PM, Raphael Cendrillon < [email protected]> wrote: > Thanks Dmitriy. I certainly understand. > > Perhaps I can find some other areas to contribute. > > On 28 Nov, 2011, at 12:37 PM, Dmitriy Lyubimov wrote: > > > I think it is certainly ok for you to try and your thoughts are even more > > appreciated because optimization of this stuff for big data that is also > > accurate seem to take more than one head to review. > > > > However, I've already planned on doing 817 in the next two months and > > finish it in Q1 if I can work out existing issues. > > The existing issues are both flow and performance and IMO require a tad > > more contemplation w.r.t. to existing flow pecularities before reliable > > flow could be figured. > > On top of it, at the point I am primary maintainer of SSVD code and I > think > > you should know that introducing modifications which at this point seem > > fairly sizable may make it more difficult for me to maintain it -- > > especially given we haven't considered effect on existing power > iterations > > yet and future issue of introducing Cholesky option (there's a pending > > issue for that as well). But I think you can catalyze that process, you > > already did a lot. > > > > > > On Mon, Nov 28, 2011 at 12:32 AM, Raphael Cendrillon < > > [email protected]> wrote: > > > >> Hi Dmitriy, > >> > >> If it's OK with you I'd like to try implementing this decoration. > >> > >> Any advice or guidance would be very much appreciated. > >> > >> Raphael. > >> > >> On 27 Nov, 2011, at 9:23 AM, Dmitriy Lyubimov (Commented) (JIRA) wrote: > >> > >>> Dmitriy Lyubimov commented on MAHOUT-817: > >>> ----------------------------------------- > >>> > >>> For the column mean bruteforce approach is probably the simplest, we 'd > >> have to decorate input of A with mean subtraction. > >>> > >>>> Add PCA options to SSVD code > >>>> ---------------------------- > >>>> > >>>> Key: MAHOUT-817 > >>>> URL: https://issues.apache.org/jira/browse/MAHOUT-817 > >>>> Project: Mahout > >>>> Issue Type: New Feature > >>>> Affects Versions: 0.6 > >>>> Reporter: Dmitriy Lyubimov > >>>> Assignee: Dmitriy Lyubimov > >>>> Fix For: Backlog > >>>> > >>>> > >>>> It seems that a simple solution should exist to integrate PCA mean > >> subtraction into SSVD algorithm without making it a pre-requisite step > and > >> also avoiding densifying the big input. > >>>> Several approaches were suggested: > >>>> 1) subtract mean off B > >>>> 2) propagate mean vector deeper into algorithm algebraically where the > >> data is already collapsed to smaller matrices > >>>> 3) --? > >>>> It needs some math done first . I'll take a stab at 1 and 2 but > >> thoughts and math are welcome. > >>> > >>> -- > >>> This message is automatically generated by JIRA. > >>> If you think it was sent incorrectly, please contact your JIRA > >> administrators: > >> > https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa > >>> For more information on JIRA, see: > >> http://www.atlassian.com/software/jira > >>> > >>> > >> > >> > >
