Re: SVM in Mahout

2013-12-24 Thread Ted Dunning
Logistic regression with L1 regularization is generally at least as good as SVM. The problem with SVM is that it uses radially symmetric regularization which doesn't learn sparse solutions very well. L1 regularization is much better for that. On Tue, Dec 24, 2013 at 10:06 AM, Steven Bourke wro

Re: SVM in Mahout

2013-12-24 Thread Steven Bourke
Just test out libsvm against log regression on a sample of your data to get an understanding of upside downside for your particular problem Sent from my iPhone > On 24 Dec 2013, at 15:55, Tharindu Rusira wrote: > > Thanks all for the words of wisdom :) , > > @Ted, I'm coming from a text mini

Re: SVM in Mahout

2013-12-24 Thread Tharindu Rusira
Thanks all for the words of wisdom :) , @Ted, I'm coming from a text mining background. Many text books recommend SVM because of its impressive performance with vectors having a larger cardinality which is the usual case when dealing with text documents. Do you think logistic regression would perf

Re: SVM in Mahout

2013-12-24 Thread unmesha sreeveni
You can paralize svm using same equations (which has slight difference) explained in http://books.google.co.in/books/about/DATA_MINING.html?id=IYc2muhCbmEC&redir_esc=y But i dont gaurentee about the performance. for some 100 MB data it takes 10 min to train the data. On Tue, Dec 24, 2013 at 3:30

Re: SVM in Mahout

2013-12-24 Thread tuku
someone tried to implement SVM in a summer google code but it turns out map reduced version of svm is too difficult to implement and they dropped the project. I bet you can train via libsvm and use just classification part with map reduce but if I have a choice I prefer logistic regression too ~--

Re: SVM in Mahout

2013-12-24 Thread Ted Dunning
You might try logistic regression with regularization for a very similar result. On Mon, Dec 23, 2013 at 11:57 PM, Sebastian Schelter < ssc.o...@googlemail.com> wrote: > Hi Tharindu, > > There is no SVM implementation in an official release. > > --sebastian > > On 24.12.2013 08:02, Tharindu Rusi

Re: SVM in Mahout

2013-12-23 Thread Sebastian Schelter
Hi Tharindu, There is no SVM implementation in an official release. --sebastian On 24.12.2013 08:02, Tharindu Rusira wrote: > Hi all, > Do we have a SVM implementation in Mahout(either sequential or mapreduce)? > I was searching in JIRA and MAHOUT-14[1] proposes a SVM implementation and > also M

Re: SVM in Mahout

2012-06-20 Thread Ted Dunning
On Wed, Jun 20, 2012 at 6:19 AM, Sebastian Schelter wrote: > I'm just asking because I review a paper where Mahout's SVM support on > M/R is mentioned :) > Interesting. We don't have anything release, I don't think. > As far as I recall All-Reduce is map + an aggregation tree that feeds > bac

Re: SVM in Mahout

2012-06-20 Thread Sebastian Schelter
I'm just asking because I review a paper where Mahout's SVM support on M/R is mentioned :) As far as I recall All-Reduce is map + an aggregation tree that feeds back the result? Giraph supports aggregators where every worker instance preaggregates the data, the master computes the final aggregati

Re: SVM in Mahout

2012-06-20 Thread Ted Dunning
No. But L1 regularization for hinge loss should give essentially identical results. We currently support logit loss but this is pluggable. This is in the sgd framework which currently lacks a map reduce implementation. Speaking of that, does anybody offhand know whether giraph supports an a