% CONDEX Demonstrates effects of large condition number on the
% accuracy of solutions to a linear system
A=hilb(8); cond(A)
b=ones(8,1);
x=A\b;
err=norm(A*x-b) % error is about 10^{-12}; pretty good!
b1=b+1.0e-6*rand(8,1); % make a small change in b
x1=A\b1; % x1 is the solution to the ``perturbed'' system
norm(x1-x,inf) % measures the largest change in x(i), i=1..8,
% can be as big as 1000!