This ugen takes in a signal, and outputs a trigger if the signal has changed. Sometimes useful for realtime-controlelr based setups.
The example is an enveloped sine wave whose frequency is modulated with sample and holds via randh. Anytime the frequency changes, it triggers the envelope via changed.
_freq var 200 1000 1 4 1 randh randh _freq set _freq get 0.6 sine _freq get changed 0.001 0.005 0.001 tenvx *