If you are already an R programmer and you want to find ways to improve the efficiency of your code, then this book is for you. While you need to be familiar with and comfortable using R, you do not need deep expertise in the language. The skills that you need to benefit from this book are:
Installing, upgrading and running R on your computer
Installing and upgrading CRAN packages within your R environment
Creating and manipulating basic data structures like vectors, matrices, lists, and data frames
Using and converting between different R data types
Performing arithmetic, logical, and other basic R operations
Using R control statements such as if, for, while, and repeat
Writing R functions
Plotting charts using R Graphics
If you are new to R and want to learn how to write R programs, there are many books, online courses, tutorials, and other resources available. Just search for them using your favorite search engine.