One place to start might be Frank Harrell's design library:

http://hesweb1.med.virginia.edu/biostat/s/help/Design/html/Overview.html

There is a function called lrm for logistic regression models.  I do not know what 
algorithm is used, however it does use MLE.   You might get more information from the 
r-help mailing list.  You can get instructions for joining through www.r-project.org.

Good Luck,

brett

-----Original Message-----
From: Ryan Schram [mailto:[EMAIL PROTECTED]
Sent: Thursday, May 29, 2003 12:36 PM
To: [EMAIL PROTECTED]
Subject: BHHH Vs. IRLS



Dear Statisticians: 

Apologies for cross-posting this (it was posted earlier to aus.stats.s).

I am using R-1.7.0 for a logit analysis, as a part of a graduate seminar
in quantitative methods. The rest of the class is using LIMDEP, which (I
think) uses the Berndt, Hall, Hall, and Hausman (BHHH) algorithm for 
doing MLE. The glm package in Splus/R uses iteratively reweighted least
squares (IRLS). What's the difference? Specifically, 

(1) Could someone point me to articles for a more social-science 
audience which discuss these algorithms? I'm especially interested in 
what conditions call for one or the other, or what are the strength and 
weaknesses of each.*

(2) Is there a way to run each algorithm in Splus/R on the same model
and see what happens? 

(3) Can I do this: 

> myfit <- glm(Y ~ X1 + X2, family=binomial(link=logit), trace=T)

> plot( trace(myfit) ~ iterations(myfit) ) 

If not, how would I go about examining the estimation steps and what 
problems should I be looking for? 

Thanks for your help in advance, 
Ryan

* I am using household survey data from a 1996 study of Papua New Guinea 
(N=1396). My models revolve around explaining living standards. This one,
for instance, will test determinants of a household reporting a 
temporary food shortage. About 20% of those surveyed said they had a 
food shortage. 

========================================================================
Ryan Schram
Doctoral Student in Anthropology 
UC San Diego
.
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