On 25/02/16 22:39, i go bananas wrote: >>real-time zero-crossing detection with sample-rate precision. > > if (incomingSignal > 0 && previousIncomingSignal < 0 || incomingSignal < > 0 || previousIncomingSignal > 0) return 1; > else return 0; fexpr~ if (($x1[0] > 0 && $x1[-1] < 0) || ($x1[0] < 0 && $x1[-1] > 0), 1, 0); Cheers, Chris. -- http://mccormick.cx/