locfreq

Purpose

Frequency localization characteristics.

Synopsis

[fm,B] = locfreq(x)

Description

locfreq computes the frequency localization characteristics of signal x. The definition used for the averaged frequency and the frequency spreading are the following:

$$\begin{eqnarray*} f_m &=& \frac{1}{E_x}\ \int_{-\infty}^{+\infty} \nu\ \vert X(\... ...int_{-\infty}^{+\infty} (\nu-f_m)^2\ \vert X(\nu)\vert^2\ d\nu } \end{eqnarray*}$$

where $E_x$ is the energy of the signal and $X(\nu)$ the Fourier transform of $x(t)$. With this definition (and the one used in loctime), the Heisenberg-Gabor inequality writes $B\ T\geq 1$.

Name	Description	Default value
x	signal
fm	averaged normalized frequency center
B	frequency spreading

Example

         z=amgauss(160,80,50).*fmconst(160,0.2);
         [fm,B]=locfreq(z); [fm,B]
         ans = 
               0.2000    0.0200

See Also

loctime.

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