matlab.md

Everything is case sensitive :

N = 1000; % size of the array
fs = 8000;

noise = randn(1,N);

Fnoise = fft(noise);

f = (0:N-1)*fs/N;

plot(f, abs(Fnoise));

For flat FFT :

N = 1000; % size of the array
M = 100;  % number of FFTs to loop. Vary this value and run again to see changes in the plot.
fs = 8000;

f = (0:N-1)*fs/N; % frequency 

Fnoise = zeros(1,N);  % Initialize an array

for i = 1:M
  noise = randn(1,N);
  Fnoise = Fnoise + fft(noise);
end

Fnoise = Fnoise / M;

plot(f, abs(Fnoise));