The book is not designed to teach you R or programming and offers little about using R for bioinformatics (apparently Chapter 5, for "Working with Character Data", and Chapter 8, about "Data Technologies", account for the "bioinformatics" part). The text is riddled with writing errors -- the author writes badly in English, however expert he may be in R -- and looks as though it has not been copy-edited at all, with all the typos, extra words, misspellings, and awkward or wrong syntax. Concepts are not introduced sequentially or systematically defined; for one example (p43) "expr" is defined as "any valid R expression" -- but "expression" is never defined.
Chapter 3, on "Object-Oriented Programming in R", I find effectively unreadable. In 3.2 appears "Inheritance allows new classes to extend, often by adding new slots...". Aside from the misuse of the transitive verb and the dangling participle, the author nowhere bothers to define "slot", but continues to use it thereafter. If he had decided for whom he is writing the book and that it was an audience advanced enough to have used an OOP language, he might have said "In R, "slot" refers to what is called a "member" in Java or C++." Then he starts talking about "dispatch", only some time later casually "defining" it two or three times. The trouble with this approach is that you never work out what you're supposed to know already, and finally decide that the author himself doesn't know or care. It would be far better to have a book of which the first third is elementary, but systematic, lead-in that you can skip if sufficiently advanced, and the second two thirds is useful stuff that refers back to the earlier material.
Problems often do not draw on material that has been presented by example; they assume that you don't need the book and can go learn the language from the onscreen R help material. After several examples of this, I got to Ex. 2.21 on p66, where the reader is told to "produce a bitmap image of a plot", with not a single example of any graphics call leading up to this. In consequence of these disconnects, I gave up working the problems, which would ordinarily be the best way to learn the language. Tellingly, the last thing the author wrote before posing this series of graphics questions was "interested readers are encouraged to explore these different settings themselves." In other words, "Why read my book? Go find out for yourself!"
I program in several languages and teach one at the introductory level. I have trouble learning from this book even at my level and would have much more as a novice programmer. For such an important language and an author who's reputed to be one of the heavy hitters in the R community, this is disappointing.
