[R] CART for 0/1 data

From: Martin Wegmann <wegmann_at_biozentrum.uni-wuerzburg.de>
Date: Sat 24 Sep 2005 - 00:33:36 EST


Dear R-user,

I tried to generate classification / regression tree with a absence/presence matrix of species (400) in different locations (50) to visualise species which are important for splitting up two locations. Rpart and tree did not work for more than 10 species which is logical due to the limited amount of locations (n=50). However the error prompt is a "+" and no specific message, but I am pretty sure that I did not enter a false sign by mistake.
Is it allowed at all to use 0/1 data for this statistical technique and if yes is there a way or different method to use all 400 species entries? Otherwise I would apply a PCA beforehand but I would prefer to have the raw species informations.

using R 2.1.1-1 (debian repos.)

regards, Martin

-- 
Martin Wegmann

DLR - German Aerospace Center
German Remote Sensing Data Center
@
Dept.of Geography
Remote Sensing and Biodiversity Unit
&&
Dept. of Animal Ecology and Tropical Biology
University of Wuerzburg
Am Hubland
97074 Würzburg

phone: +49-(0)931 - 888 4797
mobile: +49-(0)175 2091725
fax:   +49-(0)931 - 888 4961
http://www.biota-africa.org
http://www.biogis.de

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Received on Sat Sep 24 00:40:53 2005

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