Inverting a matrix is a bug. You should always use a decomposition method to solve a linear system. QR is usually a good candidate.
On Thu, Jun 23, 2011 at 8:19 AM, Sebastian Schelter (JIRA) <[email protected]>wrote: > > [ > https://issues.apache.org/jira/browse/MAHOUT-737?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13053918#comment-13053918] > > Sebastian Schelter commented on MAHOUT-737: > ------------------------------------------- > > I had a quick look at the patch, seems like most of the stuff could also be > handled by Mahout's matrix code. There's only one issue, do we have code to > invert a matrix? > > > Implicit Alternating Least Squares SVD > > -------------------------------------- > > > > Key: MAHOUT-737 > > URL: https://issues.apache.org/jira/browse/MAHOUT-737 > > Project: Mahout > > Issue Type: Improvement > > Reporter: Tamas Jambor > > Assignee: Sebastian Schelter > > Attachments: MAHOUT-737.patch, MAHOUT-737.patch > > > > > > I am sharing this Java implementation of mine that is based on the paper > - Collaborative Filtering with Implicit Datasets. The implementation is > multi-treading and can be easily extended to use it on Hadoop. In fact this > approach would possibly work with non-implicit datasets, but further testing > is needed. The algorithm is tried and tested on an implicit TV-viewing > dataset, and the performance was pretty good (details to follow). > > -- > This message is automatically generated by JIRA. > For more information on JIRA, see: http://www.atlassian.com/software/jira > > >
