跪求matlab技术问题解决，为何一直报错

只看该作者 · 2015-10-30 14:30

报错信息如下：
出错 buttord (line 55)
wp = signal.internal.sigcasttofloat(wp,'double','buttord','Wp',...

出错 Untitled2 (line 21)
[n11,wn11]=buttord(fp,fs,1,50,'s');

程序如下：
f1=2;
f2=200;
f3=500;
t=(1:100)/2000;
x1=sin(2*pi*t*f1);
x2=sin(2*pi*t*f2);
x3=sin(2*pi*t*f3);
x=sin(2*pi*t*f1)+sin(2*pi*t*f2)+sin(2*pi*t*f3);
n=(1:100); t=n/2000;
X=fft(x,512); w =(0:255)/256*1000;
x=sin(2*pi*t*f1)+sin(2*pi*t*f2)+sin(2*pi*t*f3);
Ft=100;
Fp=5;
Fs=10;
As=40 ;
Ap=3;
wp=2*pi*Fp/Ft;
ws=2*pi*Fs/Ft;
fp=2*Fp*tan(wp/2);
fs=2*Fs*tan(ws/2);
[n11,wn11]=buttord(fp,fs,1,50,'s');
[b11,a11]=butter(n11,wn11,'s');
[num11,den11]=bilinear(b11,a11,0.5);
[h,w]=freqz(num11,den11);
z11=filter(num11,den11,x);
m11=fft(z11);
figure
plot(abs(x),'g');
xlabel('t');ylabel('幅度');
title('滤波前信号的频谱');
figure
plot(abs(m11),'r');
xlabel('t’);ylabel(‘幅度');
title('滤波后信号频谱');
figure
plot(x);
xlabel('Hz’);ylabel(‘频率响应幅度');
title('滤波前信号的波形');
figure
plot(z11);
xlabel('Hz’);ylabel(‘频率响幅度');
title('滤波后的信号波形');