From hin-tak.leung at cimr.cam.ac.uk  Mon Nov  7 11:39:01 2005
From: hin-tak.leung at cimr.cam.ac.uk (Hin-Tak Leung)
Date: Mon, 07 Nov 2005 10:39:01 +0000
Subject: [Rd] Classification Trees and basic Random Forest pkg using t
 ree structures in C
In-Reply-To: <39B6DDB9048D0F4DAD42CB26AAFF0AFAFED569@usctmx1106.merck.com>
References: <39B6DDB9048D0F4DAD42CB26AAFF0AFAFED569@usctmx1106.merck.com>
Message-ID: <436F2EC5.5030508@cimr.cam.ac.uk>

Liaw, Andy wrote:
>>From: Hin-Tak Leung
<snipped>
>>Hmm, why didn't you just post a URL?
> 
> Isn't it a bit too much to assume that everyone has a personal web space
> somewhere?

Just for the sake of argument... I did assume that nih.gov is a sizeable
government organization and have official channnels for such things.
That's what government agencies do, and I suppose this software work is
in-the-line-of-duty for public consumption and therefore quite 
appropriate to put on a *.gov web site. (the same applies to *.ac.uk and 
  *.edu postings).

> For some of the data we encounter, all X variables are binary, so each data
> point can be encoded into a bitstring.  There are algorithms that take
> advantage of that.  The problem is interfacing such code with R.  I know of
> no good solutions.  As I told Grant, I thought about what he did, too, but
> the difficulty is how to pass such data structures to R.  Actually, some
> time down the road I might try to use the dendrogram class that's in R, and
> manipulate them in C.  Not sure about efficiency though. 

The best examples I have seen of manipulating foreign object is among 
the omegahat projects, like RSPerl and PSPython. Quite insteresting reading.

Hin-Tak Leung



[Rd] Classification Trees and basic Random Forest pkg using t ree structures in C
Hin-Tak Leung