Time for action – comparing using maxulp of 2

Let's do the same comparisons as in the previous Time for action tutorial, but specify a maxulp of 2 when necessary:

1. Determine the machine epsilon with the finfo function:

   eps = np.finfo(float).eps
   print "EPS", eps

   The epsilon would be:

   EPS 2.22044604925e-16

2. Do the comparisons as done in the previous Time for action tutorial, but use the assert_array_max_ulp function with the appropriate maxulp value:

   print "1", np.testing.assert_array_max_ulp(1.0, 1.0 + eps)
   print "2", np.testing.assert_array_max_ulp(1.0, 1 + 2 * eps, maxulp=2)

   The output:

   1 1.0
   2 2.0

What just happened?

We compared the same values as the previous Time for action tutorial, but specified a maxulp of 2 in the second comparison. Using the assert_array_max_ulp function with the appropriate maxulp value, these tests passed with a return value of the number of ULPs.