Geometry Boost List: Re: [geometry] Accuray issue with geometry::difference() in version Boost 1.57

Subject: Re: [geometry] Accuray issue with geometry::difference() in version Boost 1.57
From: Mikkel B. Stegmann (mikkel.stegmann_at_[hidden])
Date: 2015-04-25 08:13:40

Hello Menelaos,

thanks for your feedback. The ticket is now created:
https://svn.boost.org/trac/boost/ticket/11242

Best regards,
Mikkel B. Stegmann

On 24/04/15 15:53, Menelaos Karavelas wrote:
> Hello Mikkel.
>
> I did not yet had time to go over this. Sorry for that. I think it is 
> safer to create a ticket. This way we will keep track of it.
>
> Thanks for reporting.
>
> - m.
>
> On 24/04/2015 04:35 μμ, Mikkel B. Stegmann wrote:
>>
>> See below. Should this be elevated to a ticket?
>>
>> Best regards,
>> Mikkel B. Stegmann
>>
>> On 20/04/15 09:04, Mikkel B. Stegmann wrote:
>>>
>>> Dear Geometry list,
>>>
>>> the difference issue persists in v1.58. Apparently, it is related to 
>>> the rescaling policy introduced in v1.56 (if I read previous posts 
>>> correct). Although I'm reluctant to do so, I can mitigate the issue 
>>> be defining the BOOST_GEOMETRY_NO_ROBUSTNESS:
>>>
>>> difference polygon:  (249232.00000000003, 761089) (249232, 760980) 
>>> (265886.20000000001, 760980) (265886.20000000001, 729219) (94021, 
>>> 729219) (94021, 761089)
>>>
>>> Should this be elevated to a ticket?
>>>
>>> Best regards,
>>> Mikkel B. Stegmann
>>>
>>>
>>> On 17/04/15 10:47, Mikkel B. Stegmann wrote:
>>>> Hi Menalaos,
>>>>
>>>> somehow the results and code (including input data) got stripped in 
>>>> the
>>>> mail-version of my post. Here it is without raw-tags:
>>>>
>>>> Result using Boost v1.55:
>>>>
>>>>           249.232           761.09
>>>>           249.232           760.98
>>>>            265.89           760.98
>>>>            265.89          729.219
>>>>            94.021          729.219
>>>>            94.021           761.09
>>>>           249.232           761.09
>>>>
>>>>
>>>> Result using Boost v1.57:
>>>>
>>>> 249.232003466816           761.09
>>>>           249.232           760.98
>>>>            265.89 760.979984987659
>>>>            265.89          729.219
>>>>            94.021          729.219
>>>>            94.021           761.09
>>>> 249.232003466816           761.09
>>>>
>>>> ----
>>>>
>>>> #include <boost/foreach.hpp>
>>>> #include <boost/geometry/geometries/point_xy.hpp>
>>>> #include <boost/geometry.hpp>
>>>>
>>>> #include <cstdio>
>>>> #include <assert.h>
>>>>
>>>> int main() {
>>>>
>>>>    // 2D point with double precision
>>>>    typedef boost::geometry::model::d2::point_xy<double> BoostPoint;
>>>>
>>>>    // 2D polygon, ring type: clockwise, closed ("the first point 
>>>> must be
>>>> spatially equal to the last point")
>>>>    typedef boost::geometry::model::polygon<BoostPoint> BoostPolygon;
>>>>
>>>>    BoostPolygon rectangleA;
>>>>    rectangleA.outer().push_back(BoostPoint( 94.021, 729.219)); // 
>>>> clock-wise
>>>> points
>>>>    rectangleA.outer().push_back(BoostPoint( 94.021, 761.090));
>>>>    rectangleA.outer().push_back(BoostPoint(265.890, 761.090));
>>>>    rectangleA.outer().push_back(BoostPoint(265.890, 729.219));
>>>>    rectangleA.outer().push_back(BoostPoint( 94.021, 729.219)); // 
>>>> close
>>>>
>>>>    BoostPolygon rectangleB;
>>>>    rectangleB.outer().push_back(BoostPoint(249.232, 760.980)); // 
>>>> clock-wise
>>>> points
>>>>    rectangleB.outer().push_back(BoostPoint(249.232, 780.980));
>>>>    rectangleB.outer().push_back(BoostPoint(319.232, 780.980));
>>>>    rectangleB.outer().push_back(BoostPoint(319.232, 760.980));
>>>>    rectangleB.outer().push_back(BoostPoint(249.232, 760.980)); // 
>>>> close
>>>>
>>>>    std::list<BoostPolygon> differencePolygons;
>>>>    boost::geometry::difference(rectangleA, rectangleB, 
>>>> differencePolygons);
>>>>    assert(differencePolygons.size()==1);
>>>>
>>>>    BOOST_FOREACH(const BoostPoint &point, 
>>>> differencePolygons.front().outer())
>>>> {
>>>>      printf("%16.15g %16.15g\n", point.x(), point.y());
>>>>    }
>>>>
>>>>    return 0;
>>>> }
>>>>
>>>>
>>>>
>>>>
>>>> -- 
>>>> View this message in context: 
>>>> http://boost-geometry.203548.n3.nabble.com/Accuray-issue-with-geometry-difference-in-version-Boost-1-57-tp4026545p4026547.html
>>>> Sent from the Boost Geometry mailing list archive at Nabble.com.
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>>>
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>>
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