octave:27> yexact=@(t) expm(t*A)*y0;
octave:28> norm(y(:,ts+1)-yexact(tstar))
ans =    5.0057e-18
octave:29> norm(y(:,ts+1))
ans =    9.2540e-18
octave:30> stiff
octave:31> norm(y(:,ts+1))
ans =    2.5104e-09
octave:32> norm(y(:,ts+1)-yexact(tstar))
error: 'yexact' undefined near line 1 column 16
error: evaluating argument list element number 1
octave:32> yexact=@(t) expm(t*A)*y0;
octave:33> norm(y(:,ts+1)-yexact(tstar))
ans =    4.4925e-10
octave:34> stiff
octave:35> yexact=@(t) expm(t*A)*y0;
octave:36> norm(y(:,ts+1)-yexact(tstar))
ans =    2.1504e-10
octave:37> stiff
octave:38> stiff
octave:39> yexact=@(t) expm(t*A)*y0;
octave:40> norm(y(:,ts+1)-yexact(tstar))
ans =    1.9730e-10
octave:41> stiff
octave:42> yexact=@(t) expm(t*A)*y0;
octave:43> norm(y(:,ts+1)-yexact(tstar))
ans =    1.0080e-10
octave:44> A=100*toeplitz(sparse([1,1],[1,2],[-2,1],1,10));
octave:45> eig(A)
ans =

  -391.8986
  -368.2507
  -330.9721
  -283.0830
  -228.4630
  -171.5370
  -116.9170
   -69.0279
   -31.7493
    -8.1014

octave:46> diary off