Subject: Re: [geometry] Accuray issue with geometry::difference() in version Boost 1.57
From: Mikkel B. Stegmann (mikkel.stegmann_at_[hidden])
Date: 2015-04-24 09:35:11
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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