This has been solved by Vanuan.
These screen shots give a feel for the results:
But to really understand you need to play with the live versions, and see the zooming as it happens.
They seem similar but if you try to zoom the images, the difference becomes obvious. You can zoom by using your mousewheel, (or on a mac try 2 finger scroll on the trackpad).
Protovis: working well
D3: not zooming correctly
What I need is
- D3 based force directed graphs
- circles, text labels, and connecting lines
- Zoom should maintain the graph structure, and enlarge the viewing area
- connecting lines must zoom
- circle radius zooming is desirable, but not a firm requirement
- Text zoom is not needed. It may be desirable to zoom a bit, but not as much as the general graph, as this would not help legibility of overlapping labels
- I think you should use other technic to prevent overlapping. Not zooming text defies the purpose of zoom. http://plnkr.co/edit/cDrRQwcMOmmJmHlL6DF2?p=preview -- Vanuan 04:06, 1 September 2013 (UTC)