I'm just about finished with this patch (though I'm road tripping at the moment), but I wanted to seek some clarification on the mechanics behind DRM's matrix multiplication.
I see upon closer inspection that what is actually used is the transpose of the multiplicand (matrix A^T in A*B), thereby using only matrix rows (how DRMs are organized across HDFS). However, I didn't see any explicit transpose operation within the times() method. How is this carried out? I want to understand this little bit so I adequately replicate it in the new patch. Thanks! Shannon Apologies for the brevity, this was sent from my iPhone On Dec 29, 2010, at 1:06, "Shannon Quinn (JIRA)" <[email protected]> wrote: > > [ > https://issues.apache.org/jira/browse/MAHOUT-537?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel > ] > > Shannon Quinn updated MAHOUT-537: > --------------------------------- > > Attachment: MAHOUT-537.patch > > Updated patch. Fixes from previous patch are included, this time merged with > unrelated changes to the related files. Also removed all the commented-out > old code, and even caught and fixed a few bugs. Fully implemented > timesSquared(). All that remains is the times(DRM) job. Will update on this > very soon. > > (regarding the previous comments on this ticket: I'm using Hadoop 0.20.2) > >> Bring DistributedRowMatrix into compliance with Hadoop 0.20.2 >> ------------------------------------------------------------- >> >> Key: MAHOUT-537 >> URL: https://issues.apache.org/jira/browse/MAHOUT-537 >> Project: Mahout >> Issue Type: Improvement >> Affects Versions: 0.4 >> Reporter: Shannon Quinn >> Assignee: Shannon Quinn >> Attachments: MAHOUT-537.patch, MAHOUT-537.patch >> >> >> Convert the current DistributedRowMatrix to use the newer Hadoop 0.20.2 API, >> in particular eliminate dependence on the deprecated JobConf, using instead >> the separate Job and Configuration objects. > > -- > This message is automatically generated by JIRA. > - > You can reply to this email to add a comment to the issue online. >
