ggplot2 is a plotting system for R, based on the grammar of graphics, which tries to take the good parts of base and lattice graphics and none of the bad parts. It takes care of many of the fiddly details that make plotting a hassle (like drawing legends) as well as providing a powerful model of graphics that makes it easy to produce complex multi-layered graphics.
ggplot2 documentation is now available at docs.ggplot2.org.
You are welcome to ask ggplot2 questions on R-help, but if you'd like to participate in a more focussed mailing list, please sign up for the ggplot2 mailing list:
You must be a member to post messages, but anyone can read the archived discussions.
(You'll need to make sure you have the most recent version of R to get the most recent version of ggplot)
ggplot2: Elegant Graphics for Data Analysis is now available on amazon.com. It describes the theoretical underpinnings of ggplot2 and shows you how all the pieces fit together. The book gives you an high-level overview of the package that you just can't get from reading the documentation.
You can read sample chapters and download the book code from the book website.
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