I frequently use R (a free software environment for statistical computing and graphics) for data analysis. As almost all my data are spatial it is often good to produce a map of the results without having to export the data into another GIS package. I am often asked how to do this so I have included here the code I used to create the map you see below. It should be quite straightforward to substitute my data with your own shapefile and alter some of the parameters such as the colour and the break points to produce your own map. For those interested in more advanced spatial analysis with R I recommend this book.