Clear Filters
Clear Filters

Theoretical: Why use trapz to calculate absolute power?

6 views (last 30 days)
Hi everybody,
This more of a theoretical question and since I'm not an engineer I apologize in advance for any trouble understanding my question. I've recently seen a script that first calculated the power using pwelch method and then used trapz to calculate the integral between two frequency bins, like:
[Pxx W] = pwelch(data, window, overlap);
Pow1 = [Pow1 ; trapz(Pxx(2:6))];
Does anyone know the possible reason to take the integral of the frequencies when you are interested in power? And does this represent something different?

Answers (1)

Vinod Sudheesh
Vinod Sudheesh on 1 Apr 2015
The "pwelch" function returns the power spectral density (PSD) estimate. To compute the power contained in a frequency range, the PSD should be integrated over the required frequency range.


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!