\name{make.link}
\alias{make.link}
\title{Create a Link for GLM families}
\usage{
make.link(link)
}
\arguments{
    \item{link}{character or numeric; one of \code{"logit"},
        \code{"probit"}, \code{"cloglog"}, \code{"identity"},
        \code{"log"},  \code{"sqrt"},  \code{"1/mu^2"},
        \code{"inverse"}, or (deprecated) a non-negative number,
	say \eqn{\lambda}{lambda} resulting
        in \code{\link{power}} link \eqn{=\mu ^ \lambda}{mu ^ lambda}.
	Also (deprecated) a string like \code{"power(0.5)"} to
	indicate a call to \code{\link{power}}.
      }
}
%%-- implementation in ../R/family.R
\description{
    This function is used with the \code{\link{family}} functions in
    \code{\link{glm}()}.
    Given a link, it returns a link function, an inverse link
    function, the derivative \eqn{d\mu / d\eta}{dmu/deta} and a function
    for domain checking.
}
\value{
    A object of class \code{"link-glm"}, a list with components
    \item{linkfun}{Link function \code{function(mu)}}
    \item{linkinv}{Inverse link function \code{function(eta)}}
    \item{mu.eta}{Derivative \code{function(eta)} \eqn{d\mu / d\eta}{dmu/deta}}
    \item{valideta}{\code{function(eta)}\{ \code{TRUE} if
      \code{eta} is in the domain of \code{linkinv} \}.}
    \item{name}{a name to be used for the link}.
}
\seealso{
  \code{\link{power}}, \code{\link{glm}}, \code{\link{family}}.
}
\examples{
str(make.link("logit"))
}
\keyword{models}

