sdir2cas.m

数字信号处理的MATLAB仿真加实验指导

function[C,B,A]=sdir2cas(b,a)
Na=length(a)-1;Nb=length(b)-1;

b0=b(1);b=b/b0;
a0=a(1);a=a/a0;
C=b0/a0;
p=cplxpair(roots(a));K=floor(Na/2);
if K*2==Na
   A=zeros(K,3);
   for n=1:2:Na
      Arow=p(n:1:n+1,:);
      Arow=poly(Arow);
      A(fix((n+1)/2),:)=real(Arow);
   end
 elseif Na==1
   A=[0 real(poly(p))];
 else
    A=zeros(K+1,3);
   for n=1:2:2*K
      Arow=p(n:1:n+1,:);
      Arow=poly(Arow);
      A(fix((n+1)/2),:)=real(Arow);
      end
   A(K+1,:)=[0 real(poly(p(Na)))];
end

z=cplxpair(roots(b));K=floor(Nb/2);
if Nb==0
   B=[0 0 poly(z)];
   
   elseif K*2==Nb
   B=zeros(K,3);
   for n=1:2:Nb
      Brow=z(n:1:n+1,:);
      Brow=poly(Brow);
      B(fix((n+1)/2),:)=real(Brow);
   end
 elseif Nb==1
   B=[0 real(poly(z))];
 else
    B=zeros(K+1,3);
   for n=1:2:2*K
      Brow=z(n:1:n+1,:);
      Brow=poly(Brow);
      B(fix((n+1)/2),:)=real(Brow);
      end
   B(K+1,:)=[0 real(poly(z(Nb)))];
 end