For the following examples, the output figures are displayed as the standard output by default. During development, it is often easier to try out the code initially and produce the graph on the standard output first before finalizing the code with a script. If you have been following along with this book via a virtual machine, it is recommended that you use the VM window instead of SSH so that you can see the graphs. If you do not have access to the standard output, you can save the figure and view it after you download it (as you will see soon). Note that you will need to set the $DISPLAY variable in some of the graphs that we will produce in this section.
The following is a screenshot of the Ubuntu desktop ...
