butterd.m

里面囊括了基于matlab滤波器设计的各种.m文件

 % IIR BUTTERWORTH FILTER DESIGN
%
% [N,D] = BUTTERD(order,passedge)
% It combines the function "BUTTER" and
% "freqplot". Order is the IIR filter
% numeritor polynomial order. Passedge is
% the cut-off frequency, its value must
% be between 0 < passedge < 1.0, with 1.0 
% corresponding to half the sample rate.
% 


function [n,d] = butterd(order,passedge)

 [n,d] = butter(order,passedge);
 
 n = n(:);
 d = d(:);
 
 freqplot(n,d,'b');
 xlabel('Log Amplitude')
 title('Frequency Response');

% END