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I would like to estimates the width of the frequency band that contains 99% of the power of my signal (sound waveform), the upper and lower bounds of the band, and the power in the band. I also would like to plot the bandwidth on the power spectrum of my signal.

There is a function in the 2015 Matlab release that does this exactly: http://au.mathworks.com/help/signal/ref/obw.html

I only have the 2014a version and I was wondering if it would be possible to build the function myself. As a matlab beginner, I am not even sure where to start... Could anyone help me?

user3406207
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  • Technically, if you know someone who's got the 2015 version you could ask them to give you the code files of the implementation done by Mathworks, as the code of obw should be available to them. I am not sure how legal this is, does anyone know the policy for this? – lhcgeneva Sep 16 '15 at 10:40
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    I don't think they will give the code, they will ask him to buy it instead or upgrade the license. Computing the 99% power should not be that difficult using matlab, I just wonder if it is as simple as I think it should be (integration, cut off point of top 0.5% and cut off point of bottom 0.5%) – GameOfThrows Sep 16 '15 at 10:47
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    The answer is not unique unless you require your 99% band to be symmetrically placed. As @GameOfThrows suggests, once you've defined how you want to cut off 1% (by power), just integrate over the rest of your spectrum. – Carl Witthoft Sep 16 '15 at 14:31
  • Thanks all! I have managed to do it! – user3406207 Sep 17 '15 at 07:12

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