I posted this to matplotlib-users, and was asked to file a bug for it. So: It would appear that Axes.hist() does not handle large input values the way I was expecting it to. For example: import ...

plt.plot([1, 3, 2, 4] ) plt.show( ) This code line is the actual plotting command. Only a list of values has been plotted that represent the vertical coordinates of the points to be plotted.