[R] svm plot question

[Aimin Yan]

thanks, I did get this plot.
Before I have this problem, I did get a plot by my code.
However after I change a little my code. it doesn't work.
It is pity not saving my original code.

Now the question is the plot I get using your code is different from
what I got before.
Moreover I did remember I use plot(m.svm,p5.new,As~Cur)

Do you know why?

Thanks,

Aimin

At 06:32 AM 12/8/2006, David Meyer wrote:
>Aimin:
>
>1) Please do not spam the r-help list---one request per issue (and two
>private mails to the code author) really suffice. Not all contributors
>to the R-project are on-line 24/24, and have time to provide immediate
>answers.
>
>2) The error occurs because plot.svm() currently does not set valid
>defaults for categorical dimensions you are conditioning on for your
>2D-plot (in your example: 'P' and 'Aa') which certainly is a bug. I will
>commit a fix for the next release of e1071. For the time being, you will
>have to explicitly specify the levels of 'P' and 'Aa':
>
>plot(m.svm,p5.new,As~Cur, slice = list(P = factor("821p", levels =
>levels(P)), Aa = factor("ALA", levels = levels(Aa))))
>
>(Note that the defaults for the "slice" argument are completely
>arbitrary anyway).
>
>Thanks for pointing this out,
>
>David
>
>Aimin Yan wrote:
> > I have a question about svm in R
> >
> > I run the following code, all other is ok,
> > but plot(m.svm,p5.new,As~Cur) is not ok
> >
> > Do you know why?
> >
> > install.packages("e1071")
> > library(e1071)
> > library(MASS)
> > p5 <- read.csv("http://www.public.iastate.edu/~aiminy/data/p_5_2.csv")
> > p5.new<-subset(p5,select=-Ms)
> > p5.new$Y<-factor(p5.new$Y)
> > levels(p5.new$Y) <- list(Out=c(1), In=c(0))
> > attach(p5.new)
> > m.svm<-svm(Y~P+Aa+As+Cur,data=p5.new)
> > summary(m.svm)
> > plot(m.svm,p5.new,As~Cur)
> >
> > Here is output:
> >
> >> install.packages("e1071")
> > --- Please select a CRAN mirror for use in this session ---
> > trying URL
> > 
> 'http://rh-mirror.linux.iastate.edu/CRAN/bin/windows/contrib/2.4/e1071_1.5-16.zip'
> >
> > Content type 'application/zip' length 592258 bytes
> > opened URL
> > downloaded 578Kb
> >
> > package 'e1071' successfully unpacked and MD5 sums checked
> >
> > The downloaded packages are in
> >         C:\Documents and Settings\aiminy\Local
> > Settings\Temp\RtmpY0B2qb\downloaded_packages
> > updating HTML package descriptions
> >> library(e1071)
> > Loading required package: class
> >> library(MASS)
> >> p5 <- read.csv("http://www.public.iastate.edu/~aiminy/data/p_5_2.csv")
> >> p5.new<-subset(p5,select=-Ms)
> >> p5.new$Y<-factor(p5.new$Y)
> >> levels(p5.new$Y) <- list(Out=c(1), In=c(0))
> >> attach(p5.new)
> >> m.svm<-svm(Y~P+Aa+As+Cur,data=p5.new)
> >> summary(m.svm)
> >
> > Call:
> > svm(formula = Y ~ P + Aa + As + Cur, data = p5.new)
> >
> >
> > Parameters:
> >    SVM-Type:  C-classification
> >  SVM-Kernel:  radial
> >        cost:  1
> >       gamma:  0.04
> >
> > Number of Support Vectors:  758
> >
> >  ( 382 376 )
> >
> >
> > Number of Classes:  2
> >
> > Levels:
> >  Out In
> >
> >
> >
> >> plot(m.svm,p5.new,As~Cur)
> > Error in scale(newdata[, object$scaled, drop = FALSE], center =
> > object$x.scale$"scaled:center",  :
> >         (subscript) logical subscript too long
> >>
> >>
> >
> >
> >
>
>--
>Dr. David Meyer
>Department of Information Systems and Operations
>
>Vienna University of Economics and Business Administration
>Augasse 2-6, A-1090 Wien, Austria, Europe
>Tel: +43-1-313 36 4393
>Fax: +43-1-313 36 90 4393
>HP:  http://wi.wu-wien.ac.at/~meyer/