% m14_conditioning.m  -  well- and ill-conditioned systems of equations

  A = randn(12);              
  b = sum(A,2)               
  xexact = ones(12,1)       
  x = A\b                  
  cond(A)                 
                         
  A = hilb(12);         
  b = sum(A,2)         
  xexact
  x = A\b
  cond(A)