求高手指点

clc;clear all
N=53;alpha=(N-1)/2;Dw=2*pi/N;
m=0:N-1;Wm=Dw*m;
k1=0:floor(alpha);
k2=floor(alpha)+1:N-1;
Hrs=[0,ones(1,(N-3)/2),0.39,0.39,ones(1,(N-3)/2)];
angH=[pi/2-alpha*Dw*k1,-pi/2+alpha*Dw*(N-k2)];
H=Hrs.*exp(j*angH);
h=real(ifft(H,N));
[Hr,Ww,c,L]=Hr_type3(h);
subplot(121);stem(h,'.');
axis([0,54,-1,1]);
title('单位冲击响应');
xlabel('n');
ylabel('h(n)');grid;
subplot(122);
dbHr=20*log10(abs(Hr)/max(abs(Hr)));
plot(Ww/pi,dbHr);
xlabel('\omega/\pi');ylabel('dB');
axis([10.1,1.5,-50,5]);grid;
subplot(123)
plot(angH);
xlabel('\omega/\pi');
ylabel('angH');
grid;
Error in ==> Hilbert at 9
[Hr,Ww,c,L]=Hr_type3(h);