This R protocol shows the steps I took to create the plots for my article on stock quote correlations. You might also be interested in what the difference is between a long and a wide table and how to set up a data source in Windows 7 for R and MySQL.
The top row keeps the maps and the bottom row the respective magnifying areas. On the right hand side you will find explanations on how to use this tool and further explanatory links. The combination of placing red and green mark lines aiming at a field at a high zoom level allows you to quickly locate the plot you are looking for.