[Numpy-discussion] using assertEqual in unittest to test two np.ndarray?

josef.pktd@gmai... josef.pktd@gmai...
Fri Mar 20 16:03:40 CDT 2009


On Fri, Mar 20, 2009 at 4:49 PM, Pierre GM <pgmdevlist@gmail.com> wrote:
>
> On Mar 20, 2009, at 4:39 PM, Christopher Barker wrote:
>
>> Grissiom wrote:
>>> I know I should use array_equal to test two arrays
>>
>> Not answering your question, but I hadn't known about array_equal, so
>> when I saw this, I thought: great! I can get rid of a bunch of ugly
>> code
>> in my tests. However, it doesn't work as I would like for NaNs:
>
> Chris, have you tried assert_equal redefined in numpy.ma.testutils ?
> It was deisgned for masked arrays, but automatically deals with NaNs
>  >>> from numpy.ma.testutils import assert_equal
>  >>> a = np.array([1,2,np.nan,4])
>  >>> assert_equal(a,a)



for testing purposes it is available in numpy testing:
from numpy.testing import assert_equal,  assert_almost_equal, assert_array_equal
>>> a = np.array([  1.,   2.,  np.NaN,   4.])
>>> assert_array_equal(a,a)

does not raise AssertionError

>>> assert_array_equal(a,a+1)
Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    assert_array_equal(a,a+1)
  File "C:\Programs\Python25\lib\site-packages\numpy\testing\utils.py",
line 303, in assert_array_equal
    verbose=verbose, header='Arrays are not equal')
  File "C:\Programs\Python25\lib\site-packages\numpy\testing\utils.py",
line 295, in assert_array_compare
    raise AssertionError(msg)
AssertionError:
Arrays are not equal

(mismatch 100.0%)
 x: array([  1.,   2.,  NaN,   4.])
 y: array([  2.,   3.,  NaN,   5.])


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