chase.m

追赶法

function    x=chase (a,b,c,f) 
%定义函数chase
n=length(b);
if  n-1==length(a)
  for   i=n-1:-1:1
        a(i+1)=a(i);
       end 
end              %将a设置为n维向量
                        
c(1)=c(1)/b(1);     f(1)=f(1)/b(1);
for    i=2:n-1
      b(i)=b(i)-a(i)*c(i-1);
      c(i)=c(i)/b(i);
      f(i)=(f(i)-a(i)*f(i-1))/b(i);
end
f(n)=(f(n)-a(n)*f(n-1))/(b(n)-a(n)*c(n-1));
for     i=n-1:-1:1
      f(i)=f(i)-c(i)*f(i+1);
end
  x=f;