Question

为什么用MATLAB显示空白？

clf;
w=-pi:2*pi/255: pi;
x1=[1 3 5 7 9 11 13 15 17];
x2=[1 -2 3 -2 1];
y=conv(x1,x2);
h1=freqz(x1,1,w);
h2=freqz(x2,1,w);
hp=hi.*h2;
h3=freqz(y,1,w);
subplot(2,2,1)
plot(w/pi,abs (hp));grid
title(‘幅度谱的乘积’)
subplot(2,2,2)
plot(w/pi,abs (h3));grid
title(‘卷积后序列的幅度谱’)
subplot(2,2,3)
plot(w/pi,angle (hp));grid
title(‘相位谱的和’)
subplot(2,2,4)
plot(w/pi,angle (h3));grid
title(‘卷积后序列的相位谱’)

Answer 1

%  hp=hi.*h2;        改成     hp = h1.*h2;

% title(‘幅度谱的乘积’)     将引号全部改成半角符号

clf;

        w=-pi:2*pi/255: pi;

        x1=[1 3 5 7 9 11 13 15 17];

        x2=[1 -2 3 -2 1];

        y=conv(x1,x2);

        h1=freqz(x1,1,w);

        h2=freqz(x2,1,w);

        hp=h1.*h2;

        h3=freqz(y,1,w);

        subplot(2,2,1)

plot(w/pi,abs (hp));grid

title('幅度谱的乘积')

subplot(2,2,2)

plot(w/pi,abs (h3));grid

title('卷积后序列的幅度谱')

subplot(2,2,3)

plot(w/pi,angle (hp));grid

title('相位谱的和')

subplot(2,2,4)

plot(w/pi,angle (h3));grid

title('卷积后序列的相位谱')