[SciPy-Dev] [SciPy-User] ANN: SciPy 0.11.0 release candidate 2

Ralf Gommers ralf.gommers@gmail....
Sat Sep 8 11:31:37 CDT 2012


On Tue, Aug 14, 2012 at 3:35 PM, John Hassler <hasslerjc@comcast.net> wrote:

>
> On 8/14/2012 7:21 AM, Pauli Virtanen wrote:
> > Ralf Gommers <ralf.gommers <at> gmail.com> writes:
> > [clip]
> >> Does anyone have an idea about that test_singular failure?
> > That's very likely some problem with the underlying LAPACK library.
> > I think the problem solved is close to a numerical instability.
> >
> > The failing comparison compares eigenvalues computed by
> >
> >      eig(A, B)
> >      eig(A, B, left=False, right=False)
> >
> > which differ solely in passing 'N' vs. 'V' to DGGEV. The eigenvalue
> > property of the former is also checked and seems to pass. Interestingly,
> > the result obtained from the two seems to differ (therefore, the latter
> > is probably wrong), which appears to point to a LAPACK issue.
> >
> > Here, it would be interesting to know if the problem occurs with
> > the official Scipy binaries, or something else.
> >
>
> I installed rc2 on Python 2.7.3.  Same problem.  I get the test_singular
> error on some, but not all, of the runs.  Both are win32-superpack from
> http://sourceforge.net/projects/scipy/files/scipy/0.11.0rc2/.
>
> The error occurs on less than half but more than 1/3 (based on a very
> small sample) of the runs on both 2.7 and 3.2.
>
> I've been working on computers for more than 50 years.  Somehow, I had
> developed the delusion that they were deterministic .....
> john
>

What are we going to do about this one? I'm tempted to open a ticket for it
and mark it as knownfail on Windows for now, since it's a corner case.

Ralf


> ------------- Python 2.7 --------------------
>  >>> import scipy
>  >>> scipy.test()
> Running unit tests for scipy
> NumPy version 1.6.2
> NumPy is installed in C:\Python27\lib\site-packages\numpy
> SciPy version 0.11.0rc2
> SciPy is installed in C:\Python27\lib\site-packages\scipy
> Python version 2.7.3 (default, Apr 10 2012, 23:31:26) [MSC v.1500 32 bit
> (Intel)]
> nose version 0.11.2
>
> ======================================================================
> FAIL: test_decomp.TestEig.test_singular
> Test singular pair
> ----------------------------------------------------------------------
> Traceback (most recent call last):
>    File
> "C:\Python27\lib\site-packages\nose-0.11.2-py2.7.egg\nose\case.py", line
> 186, in runTest
>      self.test(*self.arg)
>    File
> "C:\Python27\lib\site-packages\scipy\linalg\tests\test_decomp.py", line
> 201, in test_singular
>      self._check_gen_eig(A, B)
>    File
> "C:\Python27\lib\site-packages\scipy\linalg\tests\test_decomp.py", line
> 188, in _check_gen_eig
>      err_msg=msg)
>    File "C:\Python27\lib\site-packages\numpy\testing\utils.py", line
> 800, in assert_array_almost_equal
>      header=('Arrays are not almost equal to %d decimals' % decimal))
>    File "C:\Python27\lib\site-packages\numpy\testing\utils.py", line
> 636, in assert_array_compare
>      raise AssertionError(msg)
> AssertionError:
> Arrays are not almost equal to 6 decimals
>
> array([[22, 34, 31, 31, 17],
>         [45, 45, 42, 19, 29],
>         [39, 47, 49, 26, 34],
>         [27, 31, 26, 21, 15],
>         [38, 44, 44, 24, 30]])
> array([[13, 26, 25, 17, 24],
>         [31, 46, 40, 26, 37],
>         [26, 40, 19, 25, 25],
>         [16, 25, 27, 14, 23],
>         [24, 35, 18, 21, 22]])
> (mismatch 25.0%)
>   x: array([ -2.45037885e-01 +0.00000000e+00j,
>           5.17637463e-16 -4.01120590e-08j,
>           5.17637463e-16 +4.01120590e-08j,   2.00000000e+00
> +0.00000000e+00j])
>   y: array([ -3.74550285e-01 +0.00000000e+00j,
>          -5.17716907e-17 -1.15230800e-08j,
>          -5.17716907e-17 +1.15230800e-08j,   2.00000000e+00
> +0.00000000e+00j])
>
> ----------------------------------------------------------------------
> Ran 5490 tests in 103.250s
>
> FAILED (KNOWNFAIL=14, SKIP=36, failures=1)
> <nose.result.TextTestResult run=5490 errors=0 failures=1>
>  >>>
>
> -------------- Python 3.2 --------------
>  >>> scipy.test()
> Running unit tests for scipy
> NumPy version 1.6.2
> NumPy is installed in C:\Python32\lib\site-packages\numpy
> SciPy version 0.11.0rc2
> SciPy is installed in C:\Python32\lib\site-packages\scipy
> Python version 3.2.3 (default, Apr 11 2012, 07:15:24) [MSC v.1500 32 bit
> (Intel)]
> nose version 1.0.0
>
> ======================================================================
> FAIL: test_decomp.TestEig.test_singular
> ----------------------------------------------------------------------
> Traceback (most recent call last):
>    File
> "C:\Python32\lib\site-packages\nose-1.0.0-py3.2.egg\nose\case.py", line
> 188, in runTest
>      self.test(*self.arg)
>    File
> "C:\Python32\lib\site-packages\scipy\linalg\tests\test_decomp.py", line
> 201, in test_singular
>      self._check_gen_eig(A, B)
>    File
> "C:\Python32\lib\site-packages\scipy\linalg\tests\test_decomp.py", line
> 188, in _check_gen_eig
>      err_msg=msg)
>    File "C:\Python32\lib\site-packages\numpy\testing\utils.py", line
> 800, in assert_array_almost_equal
>      header=('Arrays are not almost equal to %d decimals' % decimal))
>    File "C:\Python32\lib\site-packages\numpy\testing\utils.py", line
> 636, in assert_array_compare
>      raise AssertionError(msg)
> AssertionError:
> Arrays are not almost equal to 6 decimals
>
> array([[22, 34, 31, 31, 17],
>         [45, 45, 42, 19, 29],
>         [39, 47, 49, 26, 34],
>         [27, 31, 26, 21, 15],
>         [38, 44, 44, 24, 30]])
> array([[13, 26, 25, 17, 24],
>         [31, 46, 40, 26, 37],
>         [26, 40, 19, 25, 25],
>         [16, 25, 27, 14, 23],
>         [24, 35, 18, 21, 22]])
> (mismatch 25.0%)
>   x: array([ -2.450e-01 +0.000e+00j,   5.176e-16 -4.011e-08j, 5.176e-16
> +4.011e-08j,
>           2.000e+00 +0.000e+00j])
>   y: array([ -3.746e-01 +0.000e+00j,  -5.177e-17 -1.152e-08j, -5.177e-17
> +1.152e-08j,
>           2.000e+00 +0.000e+00j])
>
>
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