R in a Nutshell

Graphics Devices

Graphics in R are plotted on a graphics device. You can manually specify a graphics device or let R use the default device. In an interactive R environment, the default is to use the device that plots graphics on the screen. On Microsoft Windows, the windows device is used. On most Unix systems, the X11 device is used. On Mac OS X, the quartz device is used. You can generate graphics in common formats using the bmp, jpeg, png, and tiff devices. Other devices include postscript, pdf, pictex (to generate LaTeX/PicTeX), xfig, and bitmap.

Most devices allow you to specify the width, height, and point size of the output (with the width, height, and pointsize arguments, of course). For devices that generate files, you can usually use the argument name file.^[38] When you are done writing a graphic to a file, call the dev.off function to close and save the file.

In writing this book, I used the png function to generate the graphics printed in this book. For example, I used the following code to produce the first plot in Scatter Plots:

> png("scatter.1.pdf", width=4.3, height=4.3, units="in", res=72)
> attach(toxins.and.cancer)
> plot(total_toxic_chemicals/Surface_Area,deaths_total/Population)
> dev.off()

^[38] For postscript, pdf, pictex, xfig, and bitmap, the name of the argument is file. For bmp, jpeg, png, and tiff, the name of the argument is filename. However, you can safely use the argument name file because of the way R’s argument matching rules work. In general, this ...