From kirill.mueller at ivt.baug.ethz.ch  Fri Aug 15 19:55:00 2014
From: kirill.mueller at ivt.baug.ethz.ch (=?UTF-8?B?S2lyaWxsIE3DvGxsZXI=?=)
Date: Fri, 15 Aug 2014 19:55:00 +0200
Subject: [Rd] Request to review a patch for rpart
In-Reply-To: <CADwqtCMSarZp9Pv3RcOa7qazDjGCN1sNtvimu_QRVE3WpK9XpA@mail.gmail.com>
References: <53EB433D.5020101@ivt.baug.ethz.ch>
	<CADwqtCMSarZp9Pv3RcOa7qazDjGCN1sNtvimu_QRVE3WpK9XpA@mail.gmail.com>
Message-ID: <53EE4974.20908@ivt.baug.ethz.ch>

Gabriel


Thanks for your feedback. Indeed, I was not particularly clear here. The 
empty model is just a very special case in a more general setting. I'd 
have to work around this deficiency in my code -- sure I can do that, 
but I thought a generic solution should be possible. In particular, I'm 
using predict.rpart(..., type = "prob") -- this just reflects the 
observed relative frequencies.


Cheers

Kirill


On 08/15/2014 06:44 PM, Gabriel Becker wrote:
> Kirill,
>
> Perhaps I'm just being obtuse, but what are you proposing rpart do in 
> the case of an empty model?  Return a "tree" that always guesses the 
> most common label, or doesn't guess at all (NA)? It doesn't seem like 
> you'd need rpart for either of those.
>
> ~G
>
>
> On Wed, Aug 13, 2014 at 3:51 AM, Kirill M?ller 
> <kirill.mueller at ivt.baug.ethz.ch 
> <mailto:kirill.mueller at ivt.baug.ethz.ch>> wrote:
>
>     Dear list
>
>
>     For my work, it would be helpful if rpart worked seamlessly with
>     an empty model:
>
>     library(rpart); rpart(formula=y~0, data=data.frame(y=factor(1:10)))
>
>     Currently, an unrelated error (originating from na.rpart) is thrown.
>
>     At some point in the near future, I'd like to release a package to
>     CRAN which uses rpart and relies on that functionality. I have
>     prepared a patch (minor modifications at three places, and a test)
>     which I'd like to propose for inclusion in the next CRAN release
>     of rpart. The patch can be reviewed at
>     https://github.com/krlmlr/rpart/tree/empty-model, the files (based
>     on the current CRAN release 4.1-8) can be downloaded from
>     https://github.com/krlmlr/rpart/archive/empty-model.zip.
>
>     Thanks for your attention.
>
>
>     With kindest regards
>
>     Kirill M?ller
>
>     ______________________________________________
>     R-devel at r-project.org <mailto:R-devel at r-project.org> mailing list
>     https://stat.ethz.ch/mailman/listinfo/r-devel
>
>
>
>
> -- 
> Gabriel Becker
> Graduate Student
> Statistics Department
> University of California, Davis



[Rd] Request to review a patch for rpart
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