%已知序列 x(n) = 2*sin(0.48*pi*n) + cos(0.52*pi*n) ,0 =< n <=99，試繪制及它
%的離散傅里葉變換圖。
%MATLAB實現程序：
clear all
N =100;
n =0:N -1;
xn = 2*sin(0.48*pi*n) + cos(0.52*pi*n);
XK = fft(xn,n);
magXK = abs(XK);
phaXK = angle(XK);
subplot(1,2,1)
plot(n,xn)
xlabel('n');
ylabel('x(n)');
title('x(n) N =100')
subplot(1,2,2)
k = 0:length(magXK) - 1;
stem(k,magXK,'.');
xlabel('k');
ylabel('X(K)');
title('X(k) N =100');