zcross

Compute zero crossing density.

Usage

qinterp(x {type, {, sr}})

x

data vector (signal)

type

selects the type of result; 0 <= type <= 3 (default=0)

sr

sampling rate in Hz (default=1)

Result

The function counts the number of zero crossings nz of the function x[i]. The returned result is a scalar depending on nz and the argument type.

The scalar z with following meaning:

type	description
0	the number of zero crossing nz
1	the zero crossing density dz = nz / ( ncol(x) * sr) (number of zero crossings / second)
2	the average zero crossing frequenzy (in Hz) f = dz / 2
3	the average zero crossing periode length (in seconds) t = 2 / dz

See also

ipeak, formants

<function list>

Usage:

zcross(x [, type=0 {0..3}, xmin=0, srate=1])

Parameters:

type

The type of result to return (see Result)

xmin

The minimum x value.

srate

The sampling rate.

Result:

Returns a scalar:

If type=0, the number of zero-crossings.

If type=1, the density of zero-crossings (number of zero-crossings / seconds).

If type=2, the frequency of zero-crossing (density / 2).

If type=3, the period length (1 / frequency = 2 / density).

Description:

Count the number of zero-crossings in the vector x. This is a subcommand of the EVAL command.