this must be one of the followings: (i) \code{"Grafen"} (the
default), (ii) a numeric vector, or (iii) a function.}
\item{power}{The power at which heights must be raised (see below).}
this must be one of the followings: (i) \code{"Grafen"} (the
default), (ii) a numeric vector, or (iii) a function.}
\item{power}{The power at which heights must be raised (see below).}