Re: [R] Polynomial kernel in SVM in e1071 package

From: Uwe Ligges <ligges_at_statistik.uni-dortmund.de>
Date: Fri 07 Jul 2006 - 21:00:53 EST

Wuming Gong wrote:
> Dear list,
>
> In some places (for example,
> http://en.wikipedia.org/wiki/Support_vector_machine) , the polynomail
> kernel in SVM is written as (u'*v + 1)^d, while in the document of
> svm() in e1071 package, the polynomial kernel is written as
> (gamma*u'*v + coef0)^d. I am a little confused here:
>
> When doing parameter optimization (grid search or so) for polynomial
> kernel, does it need to tune four parameters, gamma, coef0, C and
> degree, or just two of them, C and degree (and fixing gamma to 1 and
> coef0 = 1)?

All of them, unless you know reasonable values, but that's very improbable.

Uwe Ligges

>
> Thanks,
>
> Wuming
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Jul 07 21:05:59 2006

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