I agree with Doug’s caution about the problem with ignoring away the “dependent” variables — values f[t] — and paying attention only to “zero”-crossings. As Adrian would point out as well, this already encodes many assumptions on what is a significant event. For example, that’s the basic problem with the “pluck” detector that Navid has coded and used
This is a big reduction about how I use plucks and triggers to ornament continueus events. In my first rough draft of GestureBending Principles (found here: http://gesturebending.weebly.com/principles-of-gesture-bending.html) I have clearly stated that triggers and and other event and onset detectors are solely used to modulate continues data with the goal of ornamenting their perceived formal structures that are driven continuously and often by the the trigger's dependant variable.
Maybe what is being referred to here as "pluck" i believe is our trigger detectors with hysteresis and debounce... Out of context this is just a very very simple element that people in our lab and elsewhere have put to different uses. Miller's bonk~ (onset detector) partially uses this and so does Vangelis's triggers and etc. We have in the recent past used this data to detect onsets and feed the onset times into our rhythm kit. Contextually meaningful modal bracketing starts from thoughtful feature extraction and the complementary rhythm kit provides a method for viewing, analyzing and manipulating the detected event onsets.