function [C,B,A]=dir2par(b,a);
 M=length(b)
 N=length(a)
[r1,p1,C]=residuez(b,a)
p=cplxpair(p1,10000000*eps)
I=cplxcomp(p1,p)
r=r1(I)
K=floor(N/2)
B=zeros(K,2)
A=zeros(K,3)
if K*2==N;
   for i=1:2:N-2
Brow=r(i:1:i+1,:)
Arow=p(i:1:i+1,:)
[Brow,Arow]=residuez(Brow,Arow,[])
B(fix((i+1)/2),:)=real(Brow)
A(fix((i+1)/2),:)=real(Arow)
end
[Trow,Arow]=residuez(r(N-1),p(N-1),[])
B(K,:)=[real(Brow) 0]
A(K,:)=[real(Arow) 0]
else
for i=1:2:N-1
Brow=r(i:1:i+1,:)
Arow=p(i:1:i+1,:)
[Brow ,Arow]=residuez(Brow,Arow,[])
B(fix((i+1)/2),:)=real(Brow)
A(fix((i+1)/2),:)=real(Arow)
end
end