%這一部分是對于我自己編的FFT函數和MATLAB中自帶的函數的計算精度的比較
%利用的只是簡單的余弦函數cos(pi*n/4)

clear
n = 0:15;
x=cos(pi*n/4);
y = FFT_self(x,16);
z = fft(x);
if(z == y)
    disp('true');
else
    disp('false');
end

figure(1)
stem(n,imag(z));
hold on;
h = stem(n,imag(y));
set(h,'MarkerFaceColor','red');
title('虛部比較');
ylabel('虛部');
xlabel('n');

figure(2)
stem(n,real(z));
hold on;
h = stem(n,real(y));
set(h,'MarkerFaceColor','red');
title('實部比較');
ylabel('實部');
xlabel('n');