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I'd like to find a way to detect a significant drop/decrease in a signal. Below is an actual example of what I'd like to accomplish, with the arrow denoting the change that I'd like to detect (only the red curve).

The data is fairly straightforward...the x-values are integers starting from zero and increasing by 1 at each data point. The y-values are also integers. I know that the dip I'd like to detect always occurs after the minimum value (denoted by the small circle). However, I'm not sure of the best way to find this drop.

What's the best methodology or algorithm for a situation like this?

Detect this event/drop in signal

  • 0
    1) Has the signal (with o without drop) some property or verify some equation? From where does it come from? 2) Has the drop some recursive character? I say this because if you see the graphic two little drops appear later.2012-06-04
  • 0
    This signal is highly unpredictable, because it's the temperature of an oven. When someone opens the door, hot air escapes and there is a drop...once it closes, it will shoot back up. The changes after the main drop aren't consisten at all. The only thing which *is* consistent is the big dip down when the door is opened.2012-06-04
  • 0
    You might want to search for "anomaly detection" algorithms and techniques.2012-06-06

3 Answers 3