Re: [R] Problem with rpart

From: Uwe Ligges <ligges_at_statistik.uni-dortmund.de>
Date: Tue 19 Sep 2006 - 23:19:54 GMT

Andrew Zachary wrote:

>
> Here is an example (though the data are too large to send ). The dataset
> is (6530 x 15). Predictors are continuous N(0,1). Trying to build a
> regression tree.
>
> fit <- rpart( y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + x10 +
> x11 + x12 + x13 + x14, data=my.data.set, weights=wts )
>
> And the output:
>
> summary( fit )
> Call:
> rpart(formula = y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + x10 +
> x11 + x12 + x13 + x14, data =my.data.set, weights = wts)
> n= 6530
>
> CP nsplit rel error
> 1 NA 0 NA

Well, I tried out a self made exmple on a 6 year old laptop right now, and it works perfectly!
Hence, you have to give some more setails about your data, as Torsten already mentioned. E.g., start with the output of str(my.data.set)
str(wts)

and perhaps this helps, otherwise, please make a small (as small as you can to reproduce) example available that reproduces the problem, e.g. on some web page.

Uwe LIgges

> Node number NA: NA observationsError in if (ff$complexity[i] < cp ||
> is.leaf[i]) cat("\n") else cat(", complexity param=", :
> missing value where TRUE/FALSE needed
>
>
> If I run this using a subset of 900 points, everything is fine.
> Similarly, if I run it using 1100 points, it dies. There are no missing
> values in the dataset. Is this simply a case where I should decrease cp?
>
> Regards,
> Andrew
>
> -----Original Message-----
> From: Torsten Hothorn [mailto:Torsten.Hothorn@rzmail.uni-erlangen.de]
> Sent: Tuesday, September 19, 2006 4:45 PM
> To: Andrew Zachary
> Cc: r-help@stat.math.ethz.ch
> Subject: Re: [R] Problem with rpart
>
>
> On Tue, 19 Sep 2006, Andrew Zachary wrote:
>
>

>>Not sure if anyone has posted on this problem ... I want to use rpart 
>>to build a binary tree on a relatively large dataset with ~1400 data 
>>points and 15 predictors. But I've noticed that rpart fails almost 
>>immediately in the call to C_s_to_rp, as that code returns nonsense. 
>>Looking at the code itself isn't terribly helpful, and there don't 
>>seem to be any hard limits coded anywhere. Does anyone have a 
>>suggestion for what might be going on?
>>

>
>
> Andrew,
>
> you need to give an _executable_ example illustrating your problem. What
> means `nonsense'?
>
> Best,
>
> Torsten
>
>
>>Thanks in advance for you help
>>Andrew Zachary
>>
>>----
>>Wetherby Partners LLC believes the information provided herein is

>
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>
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Wed Sep 20 09:20:32 2006

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