Re: Bug#813782: python-matplotlib-venn: FTBFS: [failed test] Intersection with the arc along the same circle (which means infinitely many points usually) is reported as no intersection at all.

[Konstantin Tretjakov <kt@ut.ee>]

I can't reproduce the bug (apparently it's architecture- or machine-specific), but it is 
indeed due to rounding errors. I modified the test to address this problem and hopefully 
it fixes it.

The updated code is in in github as well as pypi.

Best regards,
Konstantin.

On 13.02.2016 8:01, Andreas Tille wrote:
> Hi,
>
> as you can read below,  one test of the test suite fails.  As far as I
> can see it is possibly a rounding issue rather than a failure.  I wonder
> how the test could be tweaked to pass successfully if you share my
> opinion or what else could be done to pass the test suite successfully.
>
> Kind regards
>
>       Andreas.
>
> On Fri, Feb 05, 2016 at 09:37:32AM +0100, Chris Lamb wrote:
> > Source: python-matplotlib-venn
> > Version: 0.11-2
> > Severity: serious
> >
> > Dear Maintainer,
> >
> > python-matplotlib-venn fails to build from source in unstable/amd64:
> >
> >    [..]
> >
> >    running test
> >    running egg_info
> >    creating matplotlib_venn.egg-info
> >    writing requirements to matplotlib_venn.egg-info/requires.txt
> >    writing matplotlib_venn.egg-info/PKG-INFO
> >    writing top-level names to matplotlib_venn.egg-info/top_level.txt
> >    writing dependency_links to matplotlib_venn.egg-info/dependency_links.txt
> >    writing manifest file 'matplotlib_venn.egg-info/SOURCES.txt'
> >    warning: manifest_maker: standard file 'setup.py' not found
> >
> >    reading manifest file 'matplotlib_venn.egg-info/SOURCES.txt'
> >    writing manifest file 'matplotlib_venn.egg-info/SOURCES.txt'
> >    running build_ext
> >    ============================= test session starts ==============================
> >    platform linux2 -- Python 2.7.11, pytest-2.8.5, py-1.4.31, pluggy-0.3.1 -- /usr/bin/python2.7
> >    cachedir: ../../../.cache
> >    rootdir: /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11, inifile: setup.cfg
> >    collecting ... collected 49 items
> >
> >    matplotlib_venn/_arc.py::matplotlib_venn._arc.Arc.__init__ PASSED
> >    matplotlib_venn/_arc.py::matplotlib_venn._arc.Arc.angle_as_point PASSED
> >    ...
> >    matplotlib_venn/_venn3.py::matplotlib_venn._venn3.venn3 PASSED
> >    matplotlib_venn/_venn3.py::matplotlib_venn._venn3.venn3_circles PASSED
> >
> >    =================================== FAILURES ===================================
> >    _______________ [doctest] matplotlib_venn._arc.Arc.intersect_arc _______________
> >    339         Intersection with the arc along the same circle (which means infinitely many points usually) is reported as no intersection at all.
> >    340
> >    341         >>> a = Arc((0, 0), 1, -90, 90, True)
> >    342         >>> a.intersect_arc(Arc((1, 0), 1, 90, 270, True))
> >    343         [array([ 0.5      , -0.866...]), array([ 0.5      ,  0.866...])]
> >    344         >>> a.intersect_arc(Arc((1, 0), 1, 90, 180, True))
> >    345         [array([ 0.5      ,  0.866...])]
> >    346         >>> a.intersect_arc(Arc((1, 0), 1, 121, 239, True))
> >    347         []
> >    348         >>> a.intersect_arc(Arc((1, 0), 1, 120, 240, True))
> >    Expected:
> >        [array([ 0.5      , -0.866...]), array([ 0.5      ,  0.866...])]
> >    Got:
> >        [array([ 0.5      ,  0.8660254])]
> >
> >    /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/.pybuild/pythonX.Y_2.7/build/matplotlib_venn/_arc.py:348: DocTestFailure
> >    ===================== 1 failed, 48 passed in 0.51 seconds ======================
> >    E: pybuild pybuild:274: test: plugin custom failed with: exit code=1: cp -a README.rst /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/.pybuild/pythonX.Y_2.7/build && cd /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/.pybuild/pythonX.Y_2.7/build && python2.7 /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/setup.py test && rm README.rst
> >    dh_auto_test: pybuild --test --test-pytest -i python{version} -p 2.7 --test --system=custom --test-args=cp -a README.rst {home_dir}/build && cd {home_dir}/build && {interpreter} /home/lamby/temp/cdt.20160205085405.L1EHTA93Fx/python-matplotlib-venn-0.11/setup.py test && rm README.rst --dir . returned exit code 13