Sounds good. Let me take a look. 

Happy holidays!!

On Dec 25, 2011, at 4:16 PM, "Dmitriy Lyubimov (Commented) (JIRA)" 
<[email protected]> wrote:

> 
>    [ 
> https://issues.apache.org/jira/browse/MAHOUT-817?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13175867#comment-13175867
>  ] 
> 
> Dmitriy Lyubimov commented on MAHOUT-817:
> -----------------------------------------
> 
> bq. Thanks for merging Dmitriy. Is there anything you need from me at this 
> point?
> 
> I would always appreciate if you could poke CLI version and verify it 
> independently via matlab test for precision of computed singular values and V 
> output on a larger input. 
> 
> (I am still working on reading Mahout files into R and merging with RHadoop, 
> when it's done i will be able to verify larger tests with R.) 
> 
> -d
> 
>> 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
>> 
>>        Attachments: MAHOUT-817.patch, SSVD-PCA options.pdf, ssvd-tests.R, 
>> ssvd.R, ssvd.m
>> 
>> 
>> 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.
> 
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