GLM Logit and coefficient testing (linear combination)

-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch 
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of David 
STADELMANN
Sent: Sunday, December 18, 2005 11:32 AM
To: r-help at stat.math.ethz.ch
Subject: [R] GLM Logit and coefficient testing (linear combination)

Hi,

I am running glm logit regressions with R and I would like to 
test a linear combination of coefficients (H0: beta1=beta2 against H1:
beta1<>beta2). Is there a package for such a test or how can 
I perform it otherwise (perhaps with logLik() ???)?

Additionally I was wondering if there was no routine to 
calculate pseudo R2s for logit regressions. Currently I am 
calculating the pseudo R2 by comparing the maximum value of 
the log-Likelihood-function of the fitted model with the 
maximum log-likelihood-function of a model containing only a 
constant. Any better ideas?

Thanks a lot for your help.
David

######################################
David Stadelmann
Seminar f??r Finanzwissenschaft
Universit?? de Fribourg
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