R help - Jul 2009 - Custom Link/Family for lmer

Hello List,

I am modeling a binomial response (nest survival) and I want to incorporate
a random effect, in this case site.  I had previously been using glm with a
custom link function, but my understanding is that lmer does not currently
allow a custom link.  Therefore, I was investigating if other procedures for
mixed models will allow a custom link function.  here is the custom link
function:

logexp <- function(days = 1)
{
    linkfun <- function(mu) qlogis(mu^(1/days))
    linkinv <- function(eta) plogis(eta)^days
    mu.eta <- function(eta) days * plogis(eta)^(days-1) *
      .Call("logit_mu_eta", eta, PACKAGE = "stats")
    valideta <- function(eta) TRUE
    link <- paste("logexp(", days, ")", sep="")
    structure(list(linkfun = linkfun, linkinv = linkinv,
                   mu.eta = mu.eta, valideta = valideta, name = link),
              class = "link-glm")
}

Thanks in advance for any suggestions.

jm

	[[alternative HTML version deleted]]