ENH: add "max difference" messages to np.testing.assert_array_equal (#12591)

Example behavior:

>>> x = np.array([1, 2, 3])
>>> y = np.array([1, 2, 3.0001])
>>> np.testing.assert_allclose(x, y)
AssertionError:
Not equal to tolerance rtol=1e-07, atol=0

Mismatch: 33.3%
Max absolute difference: 0.0001
Max relative difference: 3.33322223e-05
 x: array([1, 2, 3])
 y: array([1.    , 2.    , 3.0001])

Motivation: when writing numerical algorithms, I frequently find myself
experimenting to pick the right value of `atol` and `rtol` for
`np.testing.assert_allclose()`. If I make the tolerance too generous, I risk
missing regressions in accuracy, so I usually try to pick the smallest values
for which tests pass. This change immediately reveals appropriate values to
use for these parameters, so I don't need to guess and check.

0 files changed, 0 insertions, 0 deletions