>> gl_test

GL_TEST:
  Gauss-Legendre rules of increasing order.

   N     Q(N)      Err(N)

   1     -2.053482      0.805799
   2     -2.449065       1.20138
   3     -0.593412      0.654271
   4     -1.248054   0.000371193
   5     -1.291852     0.0441689
   6     -1.240315    0.00736766
   7     -1.247179   0.000503679
   8     -1.247992   0.000309235
   9     -1.247649   3.36493e-05
  10     -1.247681   2.10663e-06
  11     -1.247684   9.84428e-07
  12     -1.247683   1.00819e-07
  13     -1.247683   2.19338e-09
  14     -1.247683   1.80387e-09
  15     -1.247683   2.08883e-10
  16     -1.247683   4.14957e-12
  17     -1.247683   1.95866e-12
  18     -1.247683   2.89768e-13
  19     -1.247683   1.59872e-14
  20     -1.247683   1.77636e-15
  21     -1.247683   6.66134e-16
>>