Norman Matloff wrote:This book is for those who wish to write code in R, as opposed to those who use R mainly for a sequence of separate, discrete statistical operations, plotting a histogram here, performing a regression analysis there. The reader's level of programming background may range from professional to novice to "took a programming course in college," but the key is that the reader wishes to write R code. Typical examples of our intended audience might be: 

• Analysts employed by, say, a hospital or government agency, who produce statistical reports on a regular basis, and need to develop production programs for this purpose. 
• Academic researchers developing statistical methodology that is either new or combines existing methods into an integrated procedure that needs to be codified for usage by the general research community. 
• Specialists in marketing, litigation support, journalism, publishing and so on who need to develop sophisticated graphical presentations of data. 
• Professional programmers who have been working in other languages, but whose employers have now assigned them to projects involving statistical analysis. 
• Students in statistical computing courses.