PowerCepstrum: Smooth...

A command to smooth the selected PowerCepstrum by averaging values at successive quefrencies.

## Settings

Quefrency averaging window (s)
  determines the width of the averaging window in the quefrency domain. By chosing a value of zero, you can prevent any smoothing in the quefrency dimension.
Number of iterations
  determines how often the averaging will take place. If chosen 2, for example, the output PowerCepstrum after the first averaging will be averaged once again.

## Examples

The figure below is the PowerCepstrum taken from an artificial /a/ vowel synthesized as follows:

`Create KlattGrid from vowel: "a", 0.3, 125, 800, 80, 1200, 80, 2300, 100, 2800, 0.1, 1000
` `To Sound
` `To PowerCepstrogram: 60, 0.002, 5000, 50
` `To PowerCepstrum (slice): 0.1
` `prominence = Get peak prominence: 60, 333.3, "Parabolic", 0.001, 0.05, "Straight", "Robust slow"
` `Draw: 0, 0, 0, 110, "yes"
` `Text top: "no", "Peak prominence = " + fixed$ (prominence, 2) + " dB"
`

After 1 iteration with an averaging window of 0.0005 s the PowerCepstrum is:

After 2 iterations with an averaging window of 0.0005 s the PowerCepstrum is: