Ask about goertzel function m file download

Actually, i want to find the m file of goertzel function in matlab but i do not find it on the website, so does anyone have this function file? Please send it to my email, thanks a lot here is my email, [e-mail]

Answer 1

[Youssef Khmou]

hi, try this :

 function [power] = Goertzel(x,Fg,Fs,N)

 % Goertzel algorithm 
 % 
 % The Goertzel algorithm searches the input signal x for a specific 
 % predetermined frequency Fg.
 %
 % Parameters:
%
% x   -  Input vector 
% Fg  -  Goertzel test frequency
% Fs  -  Sample frequenzy
% N   -  Number of samples used to calculate power
%
% power   -  Goertzel power of the input vector
%

 % Initialize vectors
power = zeros(1,N);

 % Initialize coefficients
w_hat = 2*pi*Fg/Fs;

 a1 = 2*cos(w_hat);
a2 = -1;
b0 = 1;
b1_re = -cos(w_hat);
b1_im = sin(w_hat);

 % Initialize delayline
x1 = 0;
x2 = 0;

 % Calculate Goertzel power
for n = 1:N
    xi = x(n);                 % Newest sample
        x0 = xi + a1*x1 + a2*x2;   % Calculate filter
    y_re = b0*x0 + b1_re*x1;
    y_im = b1_im*x1;

    % Opdater delayline
    x2 = x1;
    x1 = x0;

    power(n) = y_re^2 + y_im^2;
end