Sure, I'm happy to help in whatever way I can. I would like to get involved in contributing to the code, although I'm finding this quite difficult.
On 28 Nov, 2011, at 1:35 PM, Dmitriy Lyubimov wrote: > 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 >>>>> >>>>> >>>> >>>> >> >>
