The examples in the book were run in 2001, using S-PLUS (as it says).
The R package e1071 has changed since then, and hence the results it gives
have changed. However, the S-PLUS version (which has not been updated)
still gives the results in the book.
The `problem' is your expectation that R in 2006 is identical to S-PLUS
in 2001.
On Wed, 2 Aug 2006, G.C. McGuinness wrote:
> Can anyone explain the root of my problem?
>
> When I type the following code into R, I receive 42 support
> vectors insted of the 21 stated in the book 'Modern Applied
> Statistics with S':
>
> library(MASS);
> library(e1071);
> library(class);
> lcrabs <- log(crabs[,4:8]);
> (svm(crabs$sp ~ ., data = lcrabs, cost = 100, gamma = 1));
>
> By changing the value of gamma I can obtain only 21 support vectors,
> but I not sure where an explanation to my problem can be found. I
> use R 2.3.2 and the most recent version of the package 'e1071'. My
goal
> is to minimise the number of SVs for a separate data set.
There is no `R 2.3.2'.
> Many thanks, Graeme.
>
> ______________________________________________
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> 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, ripley at 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