From izmirlig at mail.nih.gov  Fri Nov  4 16:43:55 2005
From: izmirlig at mail.nih.gov (Izmirlian, Grant (NIH/NCI))
Date: Fri, 4 Nov 2005 10:43:55 -0500
Subject: [Rd] Classification Trees and basic Random Forest pkg using tree
	structures in C
Message-ID: <CE0E73903DB53F43B4B0938747F34F8A01242CB8@nihexchange7.nih.gov>

Hello R-devel:

I have written a package, called "woods", that does classification trees
(R function CT), and currently, only the most basic functionality of
Random Forest, e.g. bagged trees with choices about sample size, with/without
replacement, size of (random) subset of covariates drawn when nodes are 
split.  My reason for writing this is twofold.  First, I wanted to base
this development entirely in C (as others have done), but using data structures such as a node, pointer to node (for trees), and pointer to pointer of node (for forests) implemented in C. The algorithm which
does bagging isn't any faster (its 30% slower) than one by Leo Breiman/Adele Cutler/Andy Liaw/ Matt Weiner. The CT function runs about equally as fast
as Professor Brian Ripley's.

The only interesting feature is that the tree structure has been implemented in C. Its a neater way to carry stuff around and I am 
guessing would make future implementation easier. 

Because of its inherent redundancy from the users standpoint, it isn't
something to send to CRAN. However, I was wondering whether anyone is
interested in a copy?

Grant Izmirlian
NCI



[Rd] Classification Trees and basic Random Forest pkg using tree structures in C
Izmirlian, Grant (NIH/NCI