digidem/clearwater-map — pull request #3 by gmaclennan (2014-05-27 22:39:04+00:00)
Title: Animate scale rather than r (radius) for markers

This appears to reduce CPU usage and memory use in Chrome on Mac at least. The "bouncing" of the featured markers was causing high CPU usage. D3 was using an elastic easing function to animate both the circle radius and the stroke width. Just animating transform="scale(2)" appears to need less CPU.