zcross

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Compute zero crossing density.

Usage
zcross(x {type {, sr {, xth}}})
x
data vector (signal)
type
selects the type of result; 0 ≤ type ≤ 3 (default=0)
sr
sampling rate in Hz (default=1)
xth
threshold value (default=0); if xth is a value greater than 0, fluctuations of the function in the range -xth < x[i] < xth are ignored
Result
The function counts the number of zero crossings z of the function x[i] = f(i). The returned result is a scalar depending on z and the argument type.
type description result
0 the number of zero crossing z
1 the zero crossing density
(number of zero crossings / second)
d = z / (ncol(x) * sr)
2 the average zero crossing frequenzy (in Hz) f = d / 2
3 the average zero crossing periode length (in seconds) t = 1 / f = 2 / d
See also
f0ac

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