R is a great software environment for graphing data. R base comes with its own set of graphing capabilities, in addition, you can also use libraries like lattice to draw high quality graphs. The simplest functions are plot, and learn more about plotting by using ?plot in an R session. In general, there are two different types of plotting – high level plotting, where graphs can be drawn with just one call (e.g. plot), or low level plotting, where additional lines or points can be drawn on the existing graph (for example point() function, that helps to draw lines/points on an existing graph). You can add legends to an existing graph by using the function legend(). For more information about how to draw legends, type ?legend at the command prompt. You can also save graphs to a variety of format for further actions. You can save the graphs as jpg, png, or gif formats, using jpeg(), png(), or gif() functions. After calling the plotting devices, you must turn them off by using dev.off() function. Use ?jpeg, or ?png to learn more about them.