[R] function for "two-part" or "two-condition" models

From: Richard Chandler <rchandler_at_forwild.umass.edu>
Date: Tue 28 Jun 2005 - 05:35:30 EST


Hello,

This is an (hopefully) improved question of one I posted several weeks ago. Does anyone know of a function for fitting "two-part" models? These models are designed to handle count data with so many zeroes that they can't be fit well with zero-inflated Poisson models or other 'typical' GLMs. My understanding is that they work by first fitting a binomial model to separate the zeros from the occurrences (positive integers) before fitting a Poisson model to account for variation in abundance.

I have tried help.search("two-part") and many other similar guesses.

Thanks,
Richard

-- 
Richard Chandler, M.S. Candidate
Department of Natural Resources Conservation
UMass Amherst
(413)545-1237

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Received on Tue Jun 28 05:38:10 2005

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