fushucdtu.m

只要输入低通滤波器系数

clc
p00=[0 1/2;0 1/2];
p0=[1 1/2;0 1/2];
p1=[0 1/2;1 -1/2];
p2=[0 -1/2;0 1/2];
A=[p0,p00;
   p2,p1; 
   1,1,1,1];
B=eye(5,4);
C=A-B;
b=[0,0,0,0,1]';
x=C\b;
x
h=[0 0 x']';
t0=[p00 zeros(size(p0)) zeros(size(p0));
    p1 p0 p00;
    zeros(size(p0)) p2 p1]; 
t1=[p0 p00 zeros(size(p0));                 
   p2 p1 p0;
   zeros(size(p0)) zeros(size(p0)) p2];
  scalell1=zeros(6,100);
  a=zeros(100,15);
scall1=eye(6);
j=0;
for x=0:0.01:0.99
   j=j+1;
   for i=1:15
      a(j,i)=fix(2*x);
              x=2*x-a(j,i);
         end
      end
      for j=1:100     
     for i=1:15
        if a(j,i)==0
           scall1=scall1*t0;  
        else
           scall1=scall1*t1; 
        end   
           end  
          scalell1(1:6,j)=scall1*h;
          scall1=eye(6);
      end
sss1=[scalell1(1,1:100) scalell1(3,1:100) scalell1(5,1:100)];
sss11=[scalell1(2,1:100) scalell1(4,1:100) scalell1(6,1:100)];
x=[0:0.01:0.99];
aa1=[x-1 x x+1];
figure(1)
subplot(2,2,1)
plot(aa1,sss1)
title('(a)')
subplot(2,2,2)
plot(aa1,sss11)
title('(b)')