[Boost-bugs] [Boost C++ Libraries] #7030: distance of point to linestring with cs::spherical_equatorial gives wrong result

Subject: [Boost-bugs] [Boost C++ Libraries] #7030: distance of point to linestring with cs::spherical_equatorial gives wrong result
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-06-26 18:40:46

#7030: distance of point to linestring with cs::spherical_equatorial gives wrong
result
-------------------------------------+--------------------------------------
 Reporter:  anonymous                |       Owner:  barendgehrels
     Type:  Bugs                     |      Status:  new          
Milestone:  To Be Determined         |   Component:  geometry     
  Version:  Boost Development Trunk  |    Severity:  Problem      
 Keywords:                           |  
-------------------------------------+--------------------------------------
 The following code produces some strange results:

 typedef cs::spherical_equatorial< boost::geometry::degree > cs_type;
 typedef model::point< double , 2, cs_type > point_type;
 typedef model::linestring< point_type > linestring_type;

 point_type p( 1.0 , 1.0 );
 linestring_type l;
 l.push_back( point_type( 0.0 , 2.0 ) );
 l.push_back( point_type( 2.0 , 2.0 ) );
 l.push_back( point_type( 4.0 , 2.0 ) );

 cout << "Distance : " << boost::geometry::distance( p , l ) << endl;

 for( size_t i=1 ; i<l.size() ; ++i )
 {
     linestring_type l_tmp;
     l_tmp.push_back( l[i-1] );
     l_tmp.push_back( l[i] );
     cout << "Point distance : " << boost::geometry::distance( p , l_tmp
 ) << endl;
 }



 The output is

 Distance : 0.0174373

 Point distance : 0.0174586
 Point distance : 0.0174373

 The distance to the second segment can not be smaller than that to the
 first one. If the the coordinate system is changed to cartesian
 coordinates everything works as expected.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7030>
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