[R] How to draw the decision boundaries for LDA and Rpart object

Am Stat amstat2006 at gmail.com
Wed Aug 9 23:45:08 CEST 2006

Dr. Ripley,

Thanks very much for your help. I have used your partition tree and it works 
well.  I am not familiar with the 'tree' package but I found that the 
threshold to make a cut  returned by tree and rpart is almost the same 

Does that mean the decision boundaries for Rpart and Tree are the same for a 
same data when using the default  value of parameters, no matter what the 
structure of data  is?

Thanks very much!


----- Original Message ----- 
From: "Prof Brian Ripley" <ripley at stats.ox.ac.uk>
To: "Am Stat" <amstat2006 at gmail.com>
Cc: <r-help at stat.math.ethz.ch>
Sent: Wednesday, August 09, 2006 3:04 AM
Subject: Re: [R] How to draw the decision boundaries for LDA and Rpart 

> On Wed, 9 Aug 2006, Am Stat wrote:
>> Hello useR,
>> Could you please tell me how to draw the decision boundaries in a
>> scatterplot of the original data for a LDA or Rpart object.
> There are examples in MASS (the book).
>> For example:
>> > library(rpart)
>> >fit.rpart <- rpart(as.factor(group.id)~., data=data.frame(Data) )
>> How can I draw the cutting lines on the orignial Data?
>> Or is there any built in functions that can read the rpart object
>> 'fit.rpart' to do that?
> See partition.tree in package tree.
>> PLEASE do read the posting guide 
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> -- 
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self)
> 1 South Parks Road,                     +44 1865 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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