Iteration 2: a few Ritz values of the 20-by-20 matrix:
  1.0e+018 *

    1.3147
    1.5308
    1.8346
    2.2932
    3.0648
    4.6360

Iteration 3: a few Ritz values of the 20-by-20 matrix:
  1.0e+018 *

    1.3147
    1.5308
    1.8346
    2.2932
    3.0648
    4.6360
ans =

    4.7476
    4.0774
    3.4021
    2.7218
    2.0365
    1.3463