diagonal dominante
function [res] =diagonal_dominante(A);
n=lenght(A);
res=1;
 for i=1:n
  s=0;
   for j=1:i-1
     s=s+abs(A(i,j));
   end;
  for j=i+1:n
   s=s+abs(A(i,j));
  end;
  if s>=abs(A(i,j));
   res=0;
  end;
 end;
return;