3 \title{Add a Scale Bar to a Phylogeny Plot}
5 add.scale.bar(x, y, length = NULL, ...)
8 \item{x}{x location of the bar (can be left missing).}
9 \item{y}{y location of the bar (can be left missing).}
10 \item{length}{a numeric value giving the length of the scale bar. If
11 none is supplied, a value is calculated from the data.}
12 \item{\dots}{further arguments to be passed to \code{text}.}
15 This function adds a horizontal bar giving the scale of the branch
16 lengths to a plot of a phylogenetic tree on the current graphical
20 By default, the bar is placed in a corner of the graph depending on
21 the direction of the tree. Otherwise both \code{x} and \code{y} must
22 be specified (if only one is given it is ignored).
24 The further arguments (\code{\dots}) are used to format the text. They
25 may be \code{font}, \code{cex}, \code{col}, and so on (see examples
26 below, and the help page on \code{\link[graphics]{text}}).
28 The function \code{\link[graphics]{locator}} may be used to
29 determine the \code{x} and \code{y} arguments.
31 \author{Emmanuel Paradis \email{Emmanuel.Paradis@mpl.ird.fr}}
33 \code{\link{plot.phylo}}, \code{\link{axisPhylo}},
34 \code{\link[graphics]{locator}}
38 layout(matrix(1:2, 2, 1))
42 add.scale.bar(cex = 0.7, font = 2, col = "red")