Clear Filters
Clear Filters

How do you find average power?

120 views (last 30 days)
Nathan Jaqua
Nathan Jaqua on 20 Nov 2019
Commented: Rik on 24 May 2020
Hi y'all, I'm having an issue with this logic. I need to find the average power of but I don't see what I am doing wrong with this. Nothing shows up when I read my start.au and thusly, I'm not sure about my voiced and un_voiced segments.
clc;
clear all;
[x, Fs] = audioread('start.au');
% plot the file
plot(x, Fs);grid on;
title('raw speech data');
xlabel('samples');ylabel('amplitude');
% identify voiced segment from the speech vector. Load it in newly created
% voiced segment array
L = 300; % number of samples in sub-sample array
x_voiced = x(L:0+ L-1);
% identify unvoiced segment from the speech vector. Load it in newly created
% unvoiced segment array
x_unvoiced = x(L:0 + L-1);
% calculate average power of a voiced and unvoiced segments.
% Use avg power formula as shown in the file
P_voiced = sum(x_voiced)/L;
P_unvoiced = sum(x_unvoiced)/L;
  2 Comments
Rik
Rik on 20 Nov 2019
This time I edited your question for you. Next time, please use the tools explained on this page to make your question more readable.
As for why nothing is showing up: you are only plotting a single point. Use plot(x) or plot(1:numel(x),x) instead, and you should see a curve.
I don't really understand the rest of your code, so I'm not sure if this is already the solution you need.
Nathan Jaqua
Nathan Jaqua on 20 Nov 2019
I need to find the voiced and unvoiced portions of the signal. I thought that L:0 was what I needed in that part to find it, but I'm really not sure. Nor am I sure on how to find the average power based on the equation I attached to the question when I initially asked it.

Sign in to comment.

Accepted Answer

Daniel M
Daniel M on 21 Nov 2019
Edited: Daniel M on 21 Nov 2019
Calculating the average power of your discrete signal according to the equation in your attached figure is done as:
P = sum(x.^2)/L;
Or
P = mean(x.^2);
Or
P = rms(x)^2;
  2 Comments
Madonna Magdy
Madonna Magdy on 24 May 2020
excuse me , what's the unit of this average power ?
p= sum(x.^2)/L
Rik
Rik on 24 May 2020
That isn't really a Matlab question, but you can figure it out with unit analysis. Squaring and division affect the unit, but sum doesn't.

Sign in to comment.

More Answers (0)

Products

Community Treasure Hunt

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

Start Hunting!