[SciPy-dev] test_lstsq failure

[David M. Cooke]

On Thu, Jun 08, 2006 at 10:53:14AM +0200, Arnd Baecker wrote:
> On Thu, 8 Jun 2006, Nils Wagner wrote:
> 
> > Arnd Baecker wrote:
> > > Hi,
> > >
> > > on a 64 Bit opteron I get with current svn:
> > >
> > > ======================================================================
> > > FAIL: check_random_complex_overdet
> > > (scipy.linalg.tests.test_basic.test_lstsq)
> > > ----------------------------------------------------------------------
> > > Traceback (most recent call last):
> > >   File
> > > "/home/abaecker/BUILDS3/BuildDir/inst_numpy/lib/python2.4/site-packages/scipy/linalg/tests/test_basic.py",
> > > line 413, in check_random_complex_overdet
> > >     assert_array_almost_equal(x,direct_lstsq(a,b),3)
> > >   File
> > > "/home/abaecker/BUILDS3/BuildDir/inst_numpy/lib/python2.4/site-packages/numpy/testing/utils.py",
> > > line 233, in assert_array_almost_equal
> > >     assert cond,\
> > > AssertionError:
> > > Arrays are not almost equal (mismatch 77.7777777778%):
> > >         Array 1: [[-0.0137+0.0173j  0.0037-0.0173j -0.0114+0.0119j]
> > >  [ 0.0029-0.0356j  0.0086-0.034j   0.033 -0.0879j]
> > >  [ 0.0041-0.0097j ...
> > >         Array 2: [[-0.016 +0.0162j  0.003 -0.0171j -0.0148+0.009j ]
> > >  [-0.0017-0.0405j  0.003 -0.036j   0.0256-0.0977j]
> > >  [ 0.0038-0.0112j ...
> > >
> > > Best, Arnd
> > >
> > > _______________________________________________
> > > Scipy-dev mailing list
> > > Scipy-dev at scipy.net
> > > http://www.scipy.net/mailman/listinfo/scipy-dev
> > >
> > r1934 | cookedm | 2006-06-08 05:12:30 +0200 (Thu, 08 Jun 2006) | 4 lines
> >
> > Fix scipy.linalg.tests.test_basic.test_lstsq.check_random_complex_overdet
> > to use # of decimals, not a tolerance, as argument to
> > assert_array_almost_equal.
> > This exposes the bug again.
> 
> does "the bug" refer to the error above?
> 
> If so, then David knows about it and it is in good hands ;-)
> (BTW the time-stamp above is different from the one at
> http://projects.scipy.org/scipy/scipy/changeset/1934)

Well, I don't know what's wrong with it: I was tracking down a
DeprecationWarning, and it looks like the test case added above
was done incorrectly in such a way that it was masking the error
(it was rounding everything to 0 decimal digits :-)

btw, the time stamp is right once you correct for the time zone:
I'm currently in -0400, but Trac is showing times in -0500.

-- 
|>|\/|<
/--------------------------------------------------------------------------\
|David M. Cooke                      http://arbutus.physics.mcmaster.ca/dmc/
|cookedm at physics.mcmaster.ca