Hi everyone,
Thanks a lot for the explanationâ¦
I tried the following code to compute R2 for a regression system but it does
not work:
my_svm_model <- function(myformula, mydata, mytestdata)
{
mymodel <- svm(myformula, data=mydata)
k<- summary(mymodel)
k$r.squared
}
Can anyone please tell me what I have to change to compute R2?
Many thanks,
Nancy
>
> > Date: Tue, 29 Dec 2009 17:28:59 +0000
> > From: rip...@stats.ox.ac.uk
> > To: spec...@stat.berkeley.edu
> > CC: nancyada...@hotmail.com; > > Subject: Re: [R] R2
> >
> > On Tue, 29 Dec 2009, Phil Spector wrote:
> >
> > > Nancy -
> > > Please notice that ** is not an R operator. The caret (^) is the
> > > exponentiation operator in R.
> > > - Phil
> >
> > Actually, no,
> >
> > > 2**3
> > [1] 8
> >
> > Indeed ^ is the preferred exponentiation operator, but ** has 'always'
> > been allowed. See the following note in ?"^"
> >
> > Note:
> >
> > ʽ**ʼ is translated in the parser to ʽ^ʼ, but this was undocumented
> > for many years. It appears as an index entry in Becker _et al_
> > (1988), pointing to the help for ʽDeprecatedʼ but is not actually
> > mentioned on that page. Even though it has been deprecated in S
> > for 20 years, it is still accepted.
> >
> > I added that note in May 2008 (and it is not intended to be a
> > reference to current versions of S-PLUS, since we cannot keep checking
> > that, but that Svr4 accepted it).
> >
> > >
> > >
> > >
> > > On Tue, 29 Dec 2009, Nancy Adam wrote:
> > >
> > >>
> > >> Hi everyone,
> > >> I tried to write the code of computing R2 for a regression system but I
> > >> failed.
> > >> This is the code I use for computing RMSE:
> > >>
> > >> my_svm_model <- function(myformula, mydata, mytestdata)
> > >> {
> > >> mymodel <- svm(myformula, data=mydata)
> > >> mytest <- predict(mymodel, mytestdata)
> > >> error <- mytest - mytestdata[,1]
> > >> -sqrt(mean(error**2))
> > >>
> > >> }
> > >> can anyone please tell me what I have to change to compute R2 instead of
> > >> RMSE?
> > >>
> > >> Many thanks,
> > >> Nancy
> > >> _________________________________________________________________
> > >>
> > >>
> > >> [[alternative HTML version deleted]]
> > >>
> > >> ______________________________________________
> > >> R-help@r-project.org mailing list
> > >> https://stat.ethz.ch/mailman/listinfo/r-help
> > >> PLEASE do read the posting guide
> > >> http://www.R-project.org/posting-guide.html
> > >> and provide commented, minimal, self-contained, reproducible code.
> > >>
> > >
> > > ______________________________________________
> > > R-help@r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide
> > > http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.
> > >
> >
> > --
> > Brian D. Ripley, rip...@stats.ox.ac.uk
> > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> > University of Oxford, Tel: +44 1865 272861 (self)
> > 1 South Parks Road, +44 1865 272866 (PA)
> > Oxford OX1 3TG, UK Fax: +44 1865 272595
>
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