[R] (no subject)

[Liaw, Andy]

Jonathan,

Is there any possibility for you to send me the data, and/or the code?  I
and others have seen similar problems before, but not reproducible on the
current version, at least on the NT and Linux boxes that I have access to.
As Thomas said, it's difficult to nail these kinds of problems.  Having
reproducible data and code, at least, can help.  (It's no help that I'm no
expert in C...)

BTW, what version of the package are you using?  I've uploaded a version to
CRAN a week or two ago.

Cheers,
Andy

> -----Original Message-----
> From: Jonathan Williams
> [mailto:jonathan.williams at pharmacology.oxford.ac.uk]
> Sent: Thursday, February 13, 2003 10:52 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] (no subject)
> 
> 
> Dear R helpers,
> 
> I have a curious problem, which is that a program I have written in R
> crashes R, unpredictably. When I say that the program crashes 
> R, I mean
> that it causes R to terminate, completely. But, the operating system
> (Windows) continues OK.
> 
> The program loops around a randomForest regression. I am trying to use
> randomForest to predict the diagnosis for a set of patients 
> with dementia.
> I have 140 patients, of whom 125 have one kind of dementia and 15 have
> a different kind. We have measured about 50 variables for 
> each patient.
> The program repeatedly and randomly splits the 150 patients 
> into 75:25 
> groupings. Then it 'trains' the randomForest using the 75% 
> grouping, then 
> it 'predicts' the remaining 25% of cases. I save the 
> predictions and at
> the end compute a Receiver Operating Characteristic curve.
> 
> The program will work away happily for hours and will 
> sometimes perform
> as many as 100 cycles around the above loop. It gives quite 
> nice results.
> But, quite frequently, and unpredictably, it fails and R just 
> stops. As I 
> say, the operating system continues and any other programs 
> that are multi-
> tasking are unaffected.
> 
> If anyone could give me an idea on how to avoid this problem, I'd be
> grateful.
> 
> Thanks,
> 
> Jonathan Williams
> 
> 
> Jonathan Williams
> OPTIMA
> Radcliffe Infirmary
> Woodstock Road
> OXFORD OX2 6HE
> Tel +1865 (2)24356
> 
> ______________________________________________
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> 


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