R in a Nutshell, 2nd Edition

Customizing Charts

There are many ways to change how R plots charts. The most intuitive is through arguments to a charting function. Another way to customize charts is by setting session parameters. An additional way to change a chart is through a function that modifies a chart (for example, adding titles, trend lines, or more points). Finally, it is possible to write your own charting functions from scratch.

This section describes common arguments and parameters for controlling how charts are plotted.

Common Arguments to Chart Functions

Conveniently, most charting functions in R share some arguments. Here is a table of common arguments for charting functions.

Argument	Description
add	Should this plot be added to the existing plots on the device, or should the device be cleaned first?
axes	Controls whether axes will be plotted on the chart.
log	Controls whether points are plotted on a logarithmic scale.
type	Controls the type of graph being plotted.
xlab, ylab	Labels for x- and y-axes.
main	Main title for the plot.
sub	Subtitle for the plot.

Graphical Parameters

This section describes the graphical parameters available in the graphics package. In most cases, you can specify these parameters as arguments to graphics functions. However, you can also use the par function to set graphics parameters. The par function sets the graphics functions for a specific graphics device. These new settings will be the defaults for any new plot until you close the device.

The par function can be useful if you want to ...