Programmer Guide/Command Reference/EVAL/zcross: Difference between revisions
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{{DISPLAYTITLE:{{SUBPAGENAME}}}} | {{DISPLAYTITLE:{{SUBPAGENAME}}}} | ||
Compute zero crossing density. | Compute zero crossing density. | ||
;Usage: | ;Usage: | ||
:<code> | :<code>zcross(<var>x</var> {<var>type</var> {, <var>sr</var> {, <var>xth</var>}}})</code> | ||
:;<var>x</var>:data vector (signal) | :;<var>x</var>:data vector (signal) | ||
:;<var>type</var>:selects the type of result; 0 <= ''type'' <= 3 (default=0) | :;<var>type</var>:selects the type of result; 0 <= ''type'' <= 3 (default=0) | ||
| Line 24: | Line 23: | ||
|''t'' = 1 / ''f'' = 2 / ''d'' | |''t'' = 1 / ''f'' = 2 / ''d'' | ||
|} | |} | ||
;See also: [[../f0ac|f0ac]] | |||
[[../#Functions|<function list>]] | |||
Revision as of 12:23, 21 April 2011
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
