Summary: Add JSON serialization and automatic transitions to the brush
component, for a collection of brushes.
https://github.com/mbostock/d3/wiki/SVG-Controls#wiki-brush
The Wiki says that an automatic brush transition is a desired feature
that will eventually be included in future version of d3. This is a
bounty for someone to implement that functionality.
The prize will be awarded to an example, posted on
bl.ocks.org, that:
1) Can save the state of a collection of brushes as JSON
2) Transitions between saved states
3) Supports any d3.scale type, such as linear and ordinal scales
For this last point, please refer to Patrick Martins tutorial on
adding ordinal scales to parallel coordinates:
http://dexvis.wordpress.com/2013/01/28/d3js-parallel-lines-and-football/
You may work from any visualization that uses a collection of brushes,
though parallel coordinates is a good default if you just want to get
working.
Looking forward an elegant solution for this. Whether you modify
d3.svg.brush or build on top of it is up to you.
Bounty: 0.4 Bitcoin (~$30 USD)