lu_band.m

various matlab programs to slove various problems

function [A] = lu_band (A,p,q)
[n,n]=size(A); 
for k = 1:n-1
   for i = k+1:min(k+p,n)
      A(i,k)=A(i,k)/A(k,k);  
   end
   for j = k+1:min(k+q,n)
      for i = k+1:min(k+p,n)
         A(i,j)=A(i,j)-A(i,k)*A(k,j);
      end
   end
end
return