[R] RWeka control parameters classifiers interface

[Achim Zeileis]

On Wed, 11 Jul 2007 strinz at freenet.de wrote:

>   The problem is, that the functions
>   result=classifier(formula, data, subset, na.action, control = Weka_control(mycontrol))
>   do not seem to be manipulated by the mycontrol- arguments

Yes, they are...not all parameter changes have always an effect on the
specified learner.

>   Perhaps this should be resepected via the handlers- argument ,
>   but the documentation in this regard is rather sparse.

Handlers are not needed here.

Re: sparse docs. In case you have not seen that paper already, there is a
technical report on the ideas behind RWeka:
  http://epub.wu-wien.ac.at/dyn/openURL?id=oai:epub.wu-wien.ac.at:epub-wu-01_ba6

Re: SMO. Compare

m1 <- SMO(Species ~ ., data = iris)
m2 <- SMO(Species ~ ., data = iris, control = Weka_control(
  K = "weka.classifiers.functions.supportVector.RBFKernel"))

which yield different results so the Weka_control() works.

The same happens if you register the mySMO() interface yourself. I'm not
sure why the "E = ..." argument has no influence on the SMO, please check
the Weka docs for this particular learner.

Best,
Z