% Funktion zur Fourieranalyse
% xy Graph
% N Number of highest harmony
% p=N ??

% N=1000;
% p=N*1;
% figure(1);
% plot (xy);
% figure(2);
% fft_this(xy,N,p);

function y = fft_this(xy, N, p)

vector = 1: (length(xy)-1);
y = fft(xy, N);
x = p*vector/length(xy);

figure(3);
stem(x(1:N/2),abs(y(1:N/2)))
xlabel('Frequency(Hz)');