Plot a single point on a line graph indicating an event
I have a graph of ping times to a server. If they exceed a certain number of milliseconds (>200ms) it generates an alarm.
The line graph works great, but I can't figure out how to add a single point to the graph indicating an alarm.
The X axis data is displayed with AXIS_FORMAT_CUSTOM to indicate the number of "minutes ago" so that we have an hour's worth of data to look at. Those values are generated from the timestamp, which is a database.
The Y axis is ping times in ms.
So, when i have a ping time of 740ms that occured at timestamp, T, which was 45 minutes ago, I want to display a red dot (or even better a picture) at that point.
Please see attached screenshot.
PS. The red line at 200ms was achieved using addPoints(200,"Ping") every time I added a value for the red line. It doesn't represent data, it was how I put the 200ms limit into the chart.