请教一个MATLAB中的问题

freshbird

我的MATLAB中没有freqz_m，那如果我想调用，我该怎么在程序中加入啊？？
function [db,mag,pha,grd,w] = freqz_m(b,a);
% Modified version of freqz subroutine
% ------------------------------------
% [db,mag,pha,grd,w] = freqz_m(b,a);
%  db = Relative magnitude in dB computed over 0 to pi radians
% mag = absolute magnitude computed over 0 to pi radians
% pha = Phase response in radians over 0 to pi radians
% grd = Group delay over 0 to pi radians
%   w = 501 frequency samples between 0 to pi radians
%   b = numerator polynomial of H(z)   (for FIR: b=h)
%   a = denominator polynomial of H(z) (for FIR: a=[1])
%
[H,w] = freqz(b,a,1000,'whole');
    H = (H(1:1:501))'; w = (w(1:1:501))';
  mag = abs(H);
   db = 20*log10((mag+eps)/max(mag));
  pha = angle(H);
%  pha = unwrap(angle(H));
  grd = grpdelay(b,a,w);

freshbird

搞定了！~呵呵