doolittle.sci

function [x]=doolittle(a,b)
   n=size(a,1)
   m=eye(n,n)
   u=zeros(n,n)

   for k=1:n,
      u(1,k)=a(1,k)
   end

   for j=2:n,
      m(j,1)=a(j,1)/u(1,1)
   end

   for j=2:n-1,
      for k=j:n,
         s=0
         for z=1:j-1
            s=s+m(j,z)*u(z,k)
         end
         u(j,k)=a(j,k)-s

         for p=j:n-1,
            si=0
            for q=p+1:n,
               si=si+m(qz)*u(z,p)

m(q,p)=1/u(p,p)*(a(q,p)-si)
            end
         end
      end
   end
   w=0
   for z=1:n-1,
      w=w+m(n,z)*u(z,n)
   end
   u(n,n)=a(n,n)-w
   y=m\b
   x=u\y
endfunction