[R] Extract information from S4 object

[Jay]

Tahnk you. But, when I try the command you both suggested I get a NULL
as the results.

> names(object1 @ x.values)
NULL

Where did I go wrong?


On Feb 22, 4:34 pm, David Winsemius <dwinsem... at comcast.net> wrote:
> On Feb 22, 2010, at 8:05 AM, Jay wrote:
>
>
>
> > The function prediction() returns this:
>
> > Formal class 'performance' [package "ROCR"] with 6 slots
> >  ..@ x.name      : chr "Cutoff"
> >  ..@ y.name      : chr "Accuracy"
> >  ..@ alpha.name  : chr "none"
> >  ..@ x.values    :List of 1
> >  .. ..$ : Named num [1:89933] Inf 2.23 2.22 2.17 2.16 ...
> >  .. .. ..- attr(*, "names")= chr [1:89933] "" "36477" "56800"
> > "41667" ...
> >  ..@ y.values    :List of 1
> >  .. ..$ : num [1:89933] 0.5 0.5 0.5 0.5 0.5 ...
> >  ..@ alpha.values: list()
>
> > Now, since I want to match each prediction with its original case, I
> > need to extract the names, i.e. the information in "- attr(*,
> > "names")= chr [1:89933] "" "36477" "56800" "41667" ..." so I can use
> > it with a simple datafile[names,] query.
>
> > How do I get these names in plain number formats?
>
> Not sure what you mean by "plain number formats" but this should get  
> you a vector of "names" assuming the prediction object is named  
> "predobject":
>
> names( predobj... at x.values )
>
> If you wanted them "as.numeric", then that is the name of the  
> appropriate function.
>
> --
> David
>
>
>
> > ______________________________________________
> > R-h... at r-project.org mailing list
> >https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.