close all,
c=0.2;s=sqrt(1-c^2);
for i=1:50, A(i,i)=s^(i-1); end
for i=1:49, for j=i+1:50, A(i,j)=-c; end, end,
semilogy(diag(A),'or','linewidth',2)
legend('diagonal entries R factor')
pause,
hold,
semilogy(svd(A),'xb','linewidth',2)
legend('diagonal entries R factor','singular values')
hold off