R help - Aug 2006 - rpart output: rule extraction beyond path.rpart()

Greetings - 

 

Is there a way to automatically perform what I believe is called "rule
extraction" (by Quinlan and the machine learning community at least) for
the leaves of trees generated by rpart?  I can use path.rpart() to
automatically extract the paths to the leaves, but these can be
needlessly cumbersome.  For example, one path returned by path.rpart()
might be:

 

[1] "root"       "y>=-0.1905" "y< 0.1495" 
"z>=-0.19"   "z< 0.1785"

[6] "y>=-0.1385" "z>=-0.153"  "x< 0.37"  
"x>=-0.363"

 

But the y >= -0.1905 and z>=-.19 are both redundant, given restrictions
placed further down the tree.  Simplifying the paths by hand is feasible
for small trees but quite cumbersome when dimensionality increases.  I
can think of ways to write code to do this automatically, but would
prefer not to if it's already implemented.  I have done extensive
searching and turned up nothing, but I fear I might just be lacking the
right terminology.  Any thoughts?

 

Much appreciated,

-Ben

 

Ben Bryant

Doctoral Fellow

Pardee RAND Graduate School   

bryant@prgs.edu

 

 



--------------------

This email message is for the sole use of the intended recip...{{dropped}}