Appendix: Introduction to the Statistical Software R
The analyses in this book were conducted using the statistical software R. While similar analyses could have been assembled using different software solutions, we want to provide a quick introduction to R. R has two main advantages compared with many of its competitors: R is free. It is based on an open source project and free of charge. R grows on a daily basis. Since R is an open source project, researchers contribute to it every day. This means that R provides the most up-to-date and most complete solution possible.