freqz_m.m

包括iir,fir,功率谱

function[db,mag,pha,grd,w]=freqz_m(b,a);
[H,w]=freqz(b,a,1000,'whole');
H=H(1:501);
w=w(1:501);
mag=abs(H);
db=20*log10((mag+eps)/max(mag));
pha=angle(H);
grd=grpdelay(b,a,w);