How to overlay a vertical marker on a Flot line chart?

[Jason Zhong]

Hi,

 I am a newbie to Flot  so apologize if this is something that has been answered before. Basically I am constructing a line chart using a time based series and the data is dynamically updated so the axis/values are been updated over time and the graph is refreshed every few seconds. I need to mark certain events at some point of time on the same graph so users can see how these events are correlated to the values been displayed. Ideally these events should be marked as a vertical line overlaid on the graph so the event time and its correlation to the chart data points can be clearly seen. 

I have not been able to find a way to do this with Flot. Is there a feature that will allow me to do this or is there a way that I can use to directly access the graph canvas and do some direct drawing?


Thanks and appreciate your help,

Jason 

[Ced]

Markings/Annotations
http://www.flotcharts.org/flot/examples/annotating/index.html
https://github.com/flot/flot/blob/master/API.md#customizing-the-grid