numpy.testing.assert_array_almost_equal_nulp#
- testing.assert_array_almost_equal_nulp(x, y, nulp=1)[source]#
Compare two arrays relatively to their spacing.
This is a relatively robust method to compare two arrays whose amplitude is variable.
- Parameters:
- x, yarray_like
Input arrays.
- nulpint, optional
The maximum number of unit in the last place for tolerance (see Notes). Default is 1.
- Returns:
- None
- Raises:
- AssertionError
If the spacing between x and y for one or more elements is larger than nulp.
See also
assert_array_max_ulp
Check that all items of arrays differ in at most N Units in the Last Place.
spacing
Return the distance between x and the nearest adjacent number.
Notes
An assertion is raised if the following condition is not met:
abs(x - y) <= nulp * spacing(maximum(abs(x), abs(y)))
Examples
>>> x = np.array([1., 1e-10, 1e-20]) >>> eps = np.finfo(x.dtype).eps >>> np.testing.assert_array_almost_equal_nulp(x, x*eps/2 + x)
>>> np.testing.assert_array_almost_equal_nulp(x, x*eps + x) Traceback (most recent call last): ... AssertionError: Arrays are not equal to 1 ULP (max is 2)