On the chart, there is a configuration item called categoryAxis.select (link below). This allows selection of an X-axis range of data. We really need the same thing to be available in the Y-axis. Then, the user could drag the sides of the horizontal selection rectangle to select X-axis categories, while at the same time, optionally, the user could drag the top and bottom of a similar rectangle to select Y-axis values. Essentially the goal is for the user to be able to measure how many points lie between two points on either axis. In my personal case, this would be for a line chart.

If you need further clarification, let me know and I might be able to work with someone there directly, and show them what I was able to accomplish using a competitor's Silverlight controls.

http://docs.telerik.com/kendo-ui/api/javascript/dataviz/ui/chart#configuration-categoryAxis.select