Simple plots

The matplotlib.pyplot package contains functionality for simple plots. It is important to remember that each subsequent function call changes the state of the current plot. Eventually, we will want to either save the plot in a file or display it with the show() function. However, if we are in IPython running on a Qt or Wx backend, the figure updates interactively without waiting for the show() function. This is comparable to the way text output is printed on the fly.