MATLAB: Find the mean, energy and power of cosine function

cosine function

i am just a matlab beginner.
x[n]=2cos(0.2*pi*n) with a length of N =100 , that is, ,0<N<99 plotted
 clear all
 n=[0:99];
 x=2*cos(0.2*pi*n);
 stem(n,x);
 legend('x[n]');
 title('Sequence of 2*cos(0.2*pi*n)');
 xlabel('n');
 ylabel('x[n]');
 axis([0 99 -2 2]);
how to use MATLAB to compute the mean, and energy and power of x[n]given mean=x, energy=Ex and power=Px.

Best Answer

You can just do:
      mean(x)
      Ex = norm(x,2)^2  % the energy 
      Px = 1/numel(x)*norm(x,2)^2 % power
If you don't want to use norm(), you just use sum()
      Ex = sum(abs(x).^2)
      Px = 1/numel(x)*sum(abs(x).^2)
Note that the RMS of the signal is
      sqrt(Px)
The Signal Processing Toolbox implements this as rms()
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