This example demonstrates how to use D3’s brush component to implement focus + context zooming, with sparklines and scatterplots.
Click and drag in the small chart below to pan or zoom.
Sample data is blood pressure readings over time.
Averages for blood-pressure samples in a range are shown at the top.
Mousing over a systolic/diastolic pair highlights the pair.
Clicking on a highlighted systolic/diastolic pair opens a popup.
forked from Mike Bostock’s block Focus+Context via Brushing
Thanks to Zan Armstrong for the d3 time formatting example