PV_JensenAndersen

An FFT based onset detector UGen using a mix of extracted features. It is based on work described in Jensen and Andersen (2003), "Real-time Beat Estimation Using Feature Extraction," in: Proceedings of the Computer Music Modeling and Retrieval Symposium.

First order derivatives of the features are taken. The threshold may need to be set low to pick up on changes.

===Examples===

// observe detection
play {
 val sig = Decay.ar(Dust.ar(2), 0.1) * WhiteNoise.ar(0.25)
 val th  = MouseX.kr(0.1, 1.0, lag = 0)
 th.poll(HPZ1.kr(th).abs, "thresh")
 val tr  = PV_JensenAndersen.ar(FFT(LocalBuf(2048), sig), thresh = th)
 Seq(sig, SinOsc.ar(440) * Decay.ar(tr * 0.01, 0.1))
}