\alias{add.scale.bar}
\title{Add a Scale Bar to a Phylogeny Plot}
\usage{
-add.scale.bar(x, y, length = NULL, ...)
+add.scale.bar(x, y, length = NULL, ask = FALSE, ...)
}
\arguments{
\item{x}{x location of the bar (can be left missing).}
\item{y}{y location of the bar (can be left missing).}
\item{length}{a numeric value giving the length of the scale bar. If
none is supplied, a value is calculated from the data.}
+ \item{ask}{a logical; if \code{TRUE} the user is asked to click where
+ to draw the bar. The default is \code{FALSE}.}
\item{\dots}{further arguments to be passed to \code{text}.}
}
\description{