R help - Nov 2013 - Adding the complementary log-link to binomial() and make.link()

Dear R Help,

in my research I frequently work with binomial response models, which 
are of course part of the generalized linear models. While I do use 
common link functions such as the logit, probit and cloglog, I often 
have the need of invoking the lesser-known Complementary Log link 
(Walter W. Piegorsch, 1992, "Complementary Log Regression for 
Generalized Linear Models ", The American Statistician , Vol. 46, No. 2, 
pp. 94-99 ) which is based on the exponential distribution.

Before the release of R 3.0, I simply could do so by adding the 
following lines to the long switch command in make.link(...):

clog = {
         linkfun <- function(mu) qexp(mu)
         linkinv <- function(eta) pmax(.Machine$double.eps,pexp(eta))
         mu.eta <- function(eta) pmax(dexp(eta), .Machine$double.eps)
         valideta <- function(eta) all(eta > 0)
     },

and then add "clog" to the okLinks vector in binomial(). However, I 
recently installed R 3.0.2 and cannot get the clog link to work. I guess 
it has to do do with the fact that both make.link and binomial are 
residing in the Global environment, and does I do not know how to access 
the C routine C_binomial_dev_resids to compute the deviance residuals 
within binomial().

While I would appreciate any help on this issue, I also thought it may 
benefit other users in my research area to have the complementary log 
link included in make.link. Any chance of this happening?

Thanks a lot,
Roland Deutsch

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Roland Deutsch <roland.deutsch <at> tuwien.ac.at>
writes:
> in my research I frequently work with binomial 
response models, which 
> are of course part of the generalized linear 
models. While I do use 
> common link functions such as the logit, probit 
and cloglog, I often 
> have the need of invoking the lesser-known 
Complementary Log link 
> (Walter W. Piegorsch, 1992, "Complementary Log 
Regression for 
> Generalized Linear Models ", The American 
Statistician , Vol. 46, No. 2, 
> pp. 94-99 ) which is based on the exponential 
distribution.
> 
> Before the release of R 3.0, I simply could 
do so by adding the 
> following lines to the long switch command 
in make.link(...):
> 
> clog = {
>          linkfun <- function(mu) qexp(mu)
>          linkinv <- function(eta) pmax(.Machine$double.eps,pexp(eta))
>          mu.eta <- function(eta) pmax(dexp(eta), .Machine$double.eps)
>          valideta <- function(eta) all(eta > 0)
>      },
> 
> and then add "clog" to the okLinks vector in 
binomial(). However, I 

I wouldn't mess with make.link.  Why don't you just
define your own custom link, for example following the
example under help(family)?  This is what I did in
the psyphy package and I just checked and
they all still work under the current version of R.
> Thanks a lot,
> Roland Deutsch
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