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Thread Subject:
variability of amplitude

Subject: variability of amplitude

From: 1986

Date: 20 Aug, 2010 22:08:04

Message: 1 of 3

Hi everyone,
I'm a begginer at matlab and I need help.

I have wav file and use wavread to obtain sampled data in y and fs.

I need to find the variability of the peak-to-peak amplitude,
i.e. the average absolute base-10 logarithm of the difference
between the amplitudes of consecutive periods, multiplied by 20:

var = 1/(N-1) sum(i=1:N-1) ( |20log ( x(i+1) / x(i) )| )

where x(i) are the extracted peak-to-peak amplitude data
and N is the number of extracted fundamental frequency
periods.

Does anyone have any suggestions?
Thank you in advance,
Milana

Subject: variability of amplitude

From: ImageAnalyst

Date: 20 Aug, 2010 22:49:31

Message: 2 of 3

Well, the max() and min() functions immediately spring to mind.

Subject: variability of amplitude

From: Walter Roberson

Date: 20 Aug, 2010 23:28:24

Message: 3 of 3

On 10-08-20 05:49 PM, ImageAnalyst wrote:
> Well, the max() and min() functions immediately spring to mind.

Yes, but some peak detection logic has to be put in as well, and that makes it
more complicated. The original poster might want to put the data through a
low-pass filter first to make it easier to do peak detection.

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