DADiSP Worksheet Functions > Function Categories > Fourier Transforms and Signal Processing > RCEPS

 

RCEPS

Purpose:

Calculates the real cepstrum.

Syntax:

RCEPS(series, n)

series

-

An input series or array.

n

-

Optional. An integer, the number of samples to use. If n > length(series), the series is zero padded. Defaults to length(series).

Returns:

A real series or array.

Example:

W1: gtri(100, 1, 1/100)^3

W2: W1-delay(W1, 60)/2

W3: rceps(W1)

W4: rceps(W1, 512)

 

W2 adds a synthesized echo at 60 seconds to the data of W1.

 

W3 displays a small peak at t == 60 indicating the presence of the echo. W4 performs the same calculation with the data padded to 512 samples.

Remarks:

The complex cepstrum of a series is essentially ifft(log(fft(s))). However, the complex log calculation requires the evaluation of the continuous phase component. RCEPS ignores the phase component and calculates:

 

real(ifft(log(mag(fft(s)))))

See Also:

CCEPS

ICCEPS