Accessing the power of S. . .designed to make the language of choice for high-end research statisticians more accessible, this book demonstrates how to get the most out of the unique power of S to display, manipulate, analyze, and graph data. An Introduction to S and S-PLUS presents ideas and methods in a straightforward manner to extend computerized research possibilities for anyone involved in data management, manipulation and presentation of statistical computing, statistical modeling, or graphics. To encourage effective self-study and hands-on experimentation, the author accompanies his presentation of every concept with an example, either using data sets that are distributed with S or easily created from them. It should not be necessary to enter any data to recreate the examples in the book. Throughout, the focus is on the unique features of S (and its commercial version, S-PLUS) that do not have exact parallels in other languages. Among the topics examined are functional programming concepts, production of custom graphics, and the writing of functions.