Thank you very much Ted. This clears up a lot of the terminology for me as the concept of ridge was new to me as of this week. Question: When you state:
b) the --categories is there for the command line version which is mostly for demo purposes ... I am unclear as to what you mean. I thought all of Mahout ran from the command line. What am I missing out on? Keith On Thu, Sep 29, 2011 at 3:46 AM, Ted Dunning <[email protected]> wrote: > a) multinomial is supported > > b) the --categories is there for the command line version which is mostly > for demo purposes > > c) ridge regression originally meant L2 regularization. Nowadays people > use > it to describe either L1 or L2, but Lasso would be a better word for L1. > > d) regularization is independent of link function. Mahout only supports > inverse logistic link function (i.e. logistic regression). Other links are > easy to install. Linear regression is very easy to support, but since > there > is a strong initial solution (using Cholesky decomposition = L2 > regularization), I would recommend a from-scratch implementation. > > e) Hector's work has added some additional flexibility, mostly untried as > yet. > > On Thu, Sep 29, 2011 at 12:01 PM, Dmitriy Lyubimov <[email protected] > >wrote: > > > If by ridge estimator you imply l1 regularization, afaik you can choose > > from > > l1 and l2 gularization. > > > > Also I guess ridge implies identity link function, but I don't think > mahout > > is limited just to ridge and lasso. > > > > Ted knows for sure. > > On Sep 28, 2011 7:27 PM, "Keith Thompson" <[email protected]> > wrote: > > > Thanks Dmitriy. I also found the Mahout in Action book and checked > there. > > > In one of the examples it seems there is a --categories option which > > allows > > > the user to specify the number of categories for classification > purposes > > > (although all of the examples in the text are binary classifications). > I > > am > > > curious though as to whether the algorithm employed in Mahout uses > ridge > > > estimators or not. > > > > > > Keith > > > > > > On Wed, Sep 28, 2011 at 10:18 PM, Dmitriy Lyubimov <[email protected] > > >wrote: > > > > > >> As far as I know, Mahout implementation does multinomial > classification. > > >> On Sep 28, 2011 8:47 AM, "Keith Thompson" <[email protected]> > > wrote: > > >> > Is the version of the logistic regression classifier in Mahout for > > >> binomial > > >> > classification only or can it be used for multinomial as well? > > >> > > > >> > Regards, > > >> > Keith > > >> > > > > > > > > > > > > -- > > > *Keith Thompson* > > > Graduate Research Associate, Xerox Corporation > > > SUNY Research Foundation > > > Dept. of Systems Science and Industrial Engineering > > > Binghamton University > > > work: 585-422-6587 > > > cell: 607-793-6203 > > > -- *Keith Thompson* Graduate Research Associate, Xerox Corporation SUNY Research Foundation Dept. of Systems Science and Industrial Engineering Binghamton University work: 585-422-6587 cell: 607-793-6203
