It seems like what I am about to ask should be possible, but after a bit of experimenting so far I have been unable to figure out how:
I would like to be able to track changes in values over time. Detecting any change to a point is trivial, but I would like to be able to do something along the lines of "if a value changes 50% in 2 minutes, raise an event."
The event detector CUSUM is what I have been experimenting with so far, but unsucessfully. It is difficult to determine what parameters I should be using as there is no way to outputting the CUSUM from mango. My values are let's say 500 on average, I put the weight to 500 so the CUSUM doesn't constantly increment, and a positive limit of 700. But the CUSUM if I understand correctly always increases because it is cumulative, I only want the previous 20 or so values.
If there is way using a meta datasource to look at the 20 previous values, then I could write a script to do this, but I'm not sure if this is possible.
Anyone out there have some experience with this kinda stuff? Any insight would be appreciated!