[R] second try; writing user-defined GLM link function

Jessi Brown jessilbrown at gmail.com
Sun Apr 16 02:57:41 CEST 2006


I apologize for my earlier posting that, unbeknownst to me before, 
apparently was not in the correct format for this list. Hopefully this
attempt will go through, and no-one will hold the newbie mistake
against me.

I could really use some help in writing a new glm link function in
order to run an analysis of daily nest survival rates. I've struggled
with this for weeks now, and can at least display the contents of the
glm function, but I'm afraid I can't figure out even how to get
started at modifiying the appropriate section (fairly new at R,
complete beginner in writing functions in R!).

Essentially, all I will be doing is running a logistic regression, but
with a different link function. The link function is a modification of
the logit link:
g(theta) = natural log( (theta ^(1/t)) / (1- (theta ^(1/t)) ) ;
where t is the length of the interval between nest checks.

Could anyone help? I hope the answer is rather simple, since this just
adds the exponent (1/t) to the logit link function; but I have yet to
figure out how to do this.

Thanks in advance for any help.

cheers, Jessi Brown
Program in Ecology, Evolution, and Conservation Biology
University of Nevada-Reno




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