I've been playing with google visualization annotated timeline and so far I'm comfortable displaying the data and adding annotations, but I'm fairly confused about how to implement getting additional data when the user zooms the chart using either the zoom links at the top of the chart or the timeline below.
A great example of the implementation I'm after is google finance. When you zoom the scale at the bottom shifts and shows the overall trend for the range that is appropriate to the user.
The documentation google provides is fairly basic and dry for a novice such as myself: http://code.google.com/apis/visualization/documentation/gallery/annotatedtimeline.html
Does anyone know of a good tutorial on this subject? A python-based tutorial would be awesome!