From ape v2.1-1
0th

Percentile

##### Add a Scale Bar to a Phylogeny Plot

This function adds a horizontal bar giving the scale of the branch lengths to a plot of a phylogenetic tree on the current graphical device.

Keywords
aplot
##### Usage
add.scale.bar(x = 0, y = 1, length = NULL, ...)
##### Arguments
x
x location of the bar.
y
y location of the bar.
length
a numeric value giving the length of the scale bar. If none is supplied, a value is calculated from the data.
...
further arguments to be passed to text.
##### Details

As from version 1.4 of ape, the options of this function have been redefined, and have now default values. By default, the scale bar is plotted on the left bottom corner of the plot.

The further arguments (...) are used to format the text. They may be font, cex, col, and so on (see examples below, and the help page on text).

The function locator may be used to determine the x and y arguments.

plot.phylo, axisPhylo, locator

##### Aliases
tr <- rtree(10)
layout(matrix(1))