Overview

R is a software package for statistical computation and graphics. It is free and open-source and very flexible. It implements many modern statistical methods with good graphical support. The core of R is an interpreted computer language which allows branching and looping as well as modular programming using functions. It can be downloaded for different operating systems from the main website http://www.r-project.org/, which also contains links to manuals and documentation. For example, a relatively concise introduction to R is available at http://cran.r-project.org/doc/manuals/R-intro.pdf.

The R language is enhanced by numerous libraries. For the purposes of spatial statistics, the spatstat library has been developed. It supports the following:

• Creation, manipulation, and plotting of point patterns

• Exploratory data analysis, including intensity maps, empty space functions, nearest-neighbor distance functions, and K, L, and J functions

• Model fitting

All figures with point patterns in this book were created using the powerful commands of the spatstat library. To use it, it needs to be loaded after starting R by typing library(spatstat). A demo can be run by demo(spatstat), while typing help(spatstat) provides a help page. An introduction to spatstat is given in Baddeley & Turner (2005), and further documentation is available at www.spatstat.org.

R is equipped with all standard data types, such as scalars, vectors, arrays, and lists. Additional spatstat data types are point patterns and windows. A point pattern records the locations of the points observed in a certain region, and a window is a region in a two-dimensional space representing the “study area.”