ACKNOWLEDGMENTS
This book has benefited greatly from the input
received from many sources.
First and foremost, I must thank the technical reviewer, Hadley
Wickham, ofggplot2andplyrfame. I suggested Hadley to No Starch
Press because of his experience developing these and other highly pop-
ular R packages in CRAN, the R user-contributed code repository. As
expected, a number of Hadley’s comments resulted in improvements to
the text, especially his comments about particular coding examples, which
often began “I wonder what would happen if you wrote it this way....”In
some cases, these comments led to changing an example with one or two
versions of code to an example showing two, three, or sometimes even four
different ways to accomplish a given coding goal. This allowed for compar-
isons of the advantages and disadvantages of various approaches, which I
believe the reader will find instructive.
I am very grateful to Jim Porzak, cofounder of the Bay Area useR
Group (BARUG,http://www.bay-r.org/), for his frequent encouragement as
I was writing this book. And while on the subject of BARUG, I must thank
Jim and the other cofounder, Mike Driscoll, for establishing that lively and
stimulating forum. At BARUG, the speakers on wonderful applications of
R have always left me feeling that writing this book was a very worthy project.