Thanks. Thats interesting. In what kind of algorithms have you seen a need for this?
If I understand correctly you'd like to randomly pick between the two elements, say with equal probability? I think this wouldn't be too difficult to implement within the current framework. By the way, if you're interested in doing a quick review of the code it would be really appreciated! It's up on the reviewboard at https://reviews.apache.org/r/2955/diff/2/ On 1 Dec, 2011, at 7:30 PM, "Lance Norskog (Commented) (JIRA)" <[email protected]> wrote: > > [ > https://issues.apache.org/jira/browse/MAHOUT-880?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13161398#comment-13161398 > ] > > Lance Norskog commented on MAHOUT-880: > -------------------------------------- > > Oops sorry. This is about the set of pairwise operators available when you > combine two or more matrices: plus, minus, mean, etc. Another use case is to > just use one of the values. > >> Add some matrix method(like addition, subtraction, norm ... etc) to >> DistributedRowMatrix >> ---------------------------------------------------------------------------------------- >> >> Key: MAHOUT-880 >> URL: https://issues.apache.org/jira/browse/MAHOUT-880 >> Project: Mahout >> Issue Type: New Feature >> Components: Math >> Affects Versions: 0.6 >> Reporter: Wangda Tan >> Priority: Minor >> Labels: DistributedRowMatrix >> Attachments: MAHOUT-880.patch >> >> >> I'm a new to Mahout, I didn't find some basic matrix functions. This make >> users cannot do many tasks by CLI or API, if user get some result through >> existing map-reduce matrix operation (like svd), he cannot do farther steps. >> I make a list for it: >> 1) Addition, Subtraction >> 2) Norm (like norm-1, norm-2, norm-frobenius) >> 3) Matrix compare >> 4) Get lower triangle, upper triangle and diagonal >> 5) Get identity and zero matrix >> 6) Put two or matrix to together: A = [A1, A2] >> 7) More linear equations solver method, like Gaussian elimination (maybe >> it's hard to implement) >> 8) import and export CSV, ARFF ... (this will very useful when user want to >> reuse result from or to other applications like MATLAB) >> I want to know is there any plan to do this, if so, I can make some efforts >> to implement these. > > -- > 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 > >
