R help - Feb 2012 - Tr: Re: how to pass weka classifier options with a meta classifier in RWeka?

Le jeudi 09 f?vrier 2012 ? 15:31 +0200, Kari Ruohonen a ?crit
:
> Hi,
> I am trying to replicate a training of AttributeSelectedClassifier with
> CFsSubsetEval, BestFirst and NaiveBayes that I have initially done with
> Weka. Now, I am trying to use RWeka in R.
> 
> I have a problem of passing arguments to the CfsSubsetEval, BestFirst
> and NaiveBayes. I have first created an interface for the classifier
> with:
> 
>
AS<-make_Weka_classifier("weka/classifiers/meta/AttributeSelectedClassifier")
> 
> And then I am trying to run the classifier with:
> 
> nb.model<-AS(class~.,data=ex,
> ? ? ? ? ?control=Weka_control(
> ? ? ? ? ? ?E="weka.attributeSelection.CfsSubsetEval",
> ? ? ? ? ? ?S="weka.attributeSelection.BestFirst -D 1",
> ? ? ? ? ? ?W="weka.classifiers.bayes.NaiveBayes -D"))
> 
> But now, I get an error saying:
> 
> Error in .jcall(classifier, "V", "buildClassifier",
instances) :
> ? java.lang.Exception: Can't find class called:
> weka.classifiers.bayes.NaiveBayes -D
> 
> indicating that the way I am passing the argument "-D" to the
NaiveBayes
> is incorrect. I am uncertain from the RWeka documentation how the
> passing mechanism of Weka_control is supposed to work with meta
> classifiers. All help is greatly appreciated.
I've never tried it myself, but ?Weka_control says:
 ? ? One can use lists for options taking multiple arguments, see the
 ? ? documentation for ?SMO? for an example.

So maybe
nb.model<-AS(class~.,data=ex,
 ? ? ? ? ? ? ? ? ? ? ? ? ? control=Weka_control(
 ? ? ? ? ? ? ? ? ? ? ? ? ? ?E="weka.attributeSelection.CfsSubsetEval",
 ? ? ? ? ? ? ? ? ? ? ? ? ? ?S=list("weka.attributeSelection.BestFirst,
D=1),
 ? ? ? ? ? ? ? ? ? ? ? ? ?
?W=list("weka.classifiers.bayes.NaiveBayes", D=1)))


Cheers

On Thu, 2012-02-09 at 14:52 +0100, Milan Bouchet-Valat
wrote:
> Le jeudi 09 f?vrier 2012 ? 15:31 +0200, Kari Ruohonen a ?crit :
<snip>
> > 
> > And then I am trying to run the classifier with:
> > 
> > nb.model<-AS(class~.,data=ex,
> >          control=Weka_control(
> >            E="weka.attributeSelection.CfsSubsetEval",
> >            S="weka.attributeSelection.BestFirst -D 1",
> >            W="weka.classifiers.bayes.NaiveBayes -D"))
> > 
> > But now, I get an error saying:
> > 
> > Error in .jcall(classifier, "V",
"buildClassifier", instances) :
> >   java.lang.Exception: Can't find class called:
> > weka.classifiers.bayes.NaiveBayes -D
> > 
> > indicating that the way I am passing the argument "-D" to
the NaiveBayes
> > is incorrect. I am uncertain from the RWeka documentation how the
> > passing mechanism of Weka_control is supposed to work with meta
> > classifiers. All help is greatly appreciated.
> I've never tried it myself, but ?Weka_control says:
>      One can use lists for options taking multiple arguments, see the
>      documentation for ?SMO? for an example.
> 
> So maybe
> nb.model<-AS(class~.,data=ex,
>                            control=Weka_control(
>                            
E="weka.attributeSelection.CfsSubsetEval",
>                             S=list("weka.attributeSelection.BestFirst,
D=1),
>                            
W=list("weka.classifiers.bayes.NaiveBayes", D=1)))
> 
> 
> Cheers
Hi and thanks for the suggestion. Unfortunately, it results in a similar
error:

Error in .jcall(classifier, "V", "buildClassifier",
instances) :
  java.lang.Exception: Can't find class called:
weka.classifiers.bayes.NaiveBayes -D 1

regards, Kari