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From Fernando Santos <fernandoleandro1...@gmail.com>
Subject Re: SVM Implementation for mahout?
Date Sun, 08 Dec 2013 17:14:32 GMT
Hello Lucas,

Thanks for the advice. It seems that this patch is a working implementation
of MLP (https://issues.apache.org/jira/browse/MAHOUT-1265). I'll give it a
try.

Have you ever used it? If so, any advices?

Now just a theoretical doubt. In a text classification example, what would
it mean to have features that are high correlated?  I mean, in this case
our features are basically words, do you have an example of how these
features can not be independant? This concept is not really clear in my
mind...

Thanks


2013/12/8 Lucas Fernandes Brunialti <lbrunialti@igcorp.com.br>

> Hello Fernando,
>
> The naive bayes approach makes the assumption that your features are
> independent, if your featurea have a high correlation, naive bayes won't be
> a good choice.
>
> I would advice you to try the neural networks (mlp), it can get a better
> decision surface than logistic regression...
>
> Best.
>
> Lucas.
> On Dec 7, 2013 6:53 PM, "Fernando Santos" <fernandoleandro1991@gmail.com>
> wrote:
>
> > Hello Suneel,
> >
> > I want to check if any better performance is reached with SVM.
> >
> > I've been using naive bayes, but my data is quite unbalanced and
> therefore
> > I'm getting pretty bad results with it. I also tried the complementary
> > naive bayes, but got the same bad results. I read about this difference
> > between NaiveBayes performance of Weka and Mahout implementations and
> maybe
> > that's the cause (
> >
> >
> http://mail-archives.apache.org/mod_mbox/mahout-user/201109.mbox/%3CCABdaxxiJTfV9nhQXxPYd72RRsv-H60Ps13H0PUNd2iNJX70BnA@mail.gmail.com%3E
> > ).
> >
> > I also tried logistic regression and got around 77% accuracy. So maybe
> with
> > SVM it could be better.
> >
> >
> > 2013/12/7 Suneel Marthi <suneel_marthi@yahoo.com>
> >
> > > Any specific reasons u r looking for an SVM implementation only?
> > > R u sure that those patches r still relevant given the codebase today?
> > >
> > >
> > >
> > >
> > >
> > > On Saturday, December 7, 2013 2:58 PM, Fernando Santos <
> > > fernandoleandro1991@gmail.com> wrote:
> > >
> > > Thanks Manuel.
> > >
> > > It seems that these two (
> > https://issues.apache.org/jira/browse/MAHOUT-334
> > > and https://issues.apache.org/jira/browse/MAHOUT-232) patches might
> > work,
> > > although not in parallel.
> > >
> > > Does anyone has sucessfully used any of these two patches already and
> > could
> > > share some comments about it?
> > >
> > > Thanks
> > >
> > >
> > > 2013/12/6 Manuel Blechschmidt <Manuel.Blechschmidt@gmx.de>
> > >
> > > > Hi Fernando,
> > > > there are some patches and some discussions:
> > > >
> > > > SVM:
> > > > https://issues.apache.org/jira/browse/MAHOUT-334
> > > > https://issues.apache.org/jira/browse/MAHOUT-232
> > > > https://issues.apache.org/jira/browse/MAHOUT-14
> > > > https://issues.apache.org/jira/browse/MAHOUT-227
> > > >
> > > > /Manuel
> > > >
> > > > On 06.12.2013, at 19:14, Fernando Santos wrote:
> > > >
> > > > > Hello,
> > > > >
> > > > > Is there any tested SVM implementation for Mahout?
> > > > >
> > > > > Mahout in action says there is a sequential implementation, but
> > > > > "Experimental still". I couldn't find this implementation.
> > > > >
> > > > > Thanks
> > > > >
> > > > > --
> > > > > Fernando Santos
> > > > > +55 61 8129 8505
> > > >
> > > > --
> > > > Manuel Blechschmidt
> > > > M.Sc. IT Systems Engineering
> > > > Dortustr. 57
> > > > 14467 Potsdam
> > > > Mobil: 0173/6322621
> > > > Twitter: http://twitter.com/Manuel_B
> > >
> > > >
> > > >
> > >
> > >
> > > --
> > > Fernando Santos
> > > +55 61 8129 8505
> > >
> >
> >
> >
> > --
> > Fernando Santos
> > +55 61 8129 8505
> >
>



-- 
Fernando Santos
+55 61 8129 8505

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