

   CCrreeaattee aa LLiinnkk ffoorr GGLLMM ffaammiilliieess

        make.link(link)

   AArrgguummeennttss::

       link: character or numeric; one of `"logit"', `"pro-
             bit"', `"cloglog"', `"identity"', `"log"',
             `"sqrt"',  `"1/mu^2"', `"inverse"', or number, say
             lambda resulting in power link mu ^ lambda.

   DDeessccrriippttiioonn::

        This function is used with the `family' functions in
        `glm()'.  Given a link, it returns a link function, an
        inverse link function, the derivative dmu/deta and a
        function for domain checking.

   VVaalluuee::

        A list with components

    linkfun: Link function `function(mu)'

    linkinv: Inverse link function `function(eta)'

     mu.eta: Derivative `function(eta)' dmu/deta

   valideta: `function(eta)'{ `TRUE' if all of `eta' is in the
             domain of `linkinv' }.

   SSeeee AAllssoo::

        `glm', `family'.

   EExxaammpplleess::

        str(make.link("logit"))

        l2 <- make.link(2)
        l2$linkfun(0:3)# 0 1 4 9
        l2$mu.eta(eta= 1:2)#= 1/(2*sqrt(eta))

