https://svn.boost.org/trac10/ticket/7462 <p> The following data gives wrong results with geometry::union. </p> <pre class="wiki">float data1[][2] = {{0,0}, {-0.3681253195,0.9297761917}, {2.421203136,2.034152031}, {2.789328575,1.104375958}, {0,0}}; float data2[][2] = {{2.76143527,1.093332171}, {2.076887131,1.822299719}, {4.263789177,3.875944376}, {4.948337555,3.146976948}, {2.76143527,1.093332171}}; polygon_t p1, p2; boost::geometry::append(p1, data1); boost::geometry::append(p2, data2); std::vector&lt;polygon_t&gt; output; boost::geometry::union_(p1, p2, output); </pre><p> Please find attached the whole main file and program output. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/7462 Trac 1.4.3 Danvil <danvil@…> Tue, 02 Oct 2012 22:26:42 GMT https://svn.boost.org/trac10/ticket/7462 https://svn.boost.org/trac10/ticket/7462 <ul> <li><strong>attachment</strong> → <span class="trac-field-new">boost_geometry_union_bug.cpp</span> </li> </ul> Ticket Danvil <danvil@…> Tue, 02 Oct 2012 22:27:44 GMT https://svn.boost.org/trac10/ticket/7462 https://svn.boost.org/trac10/ticket/7462 <ul> <li><strong>attachment</strong> → <span class="trac-field-new">boost_geometry_union_bug_output.txt</span> </li> </ul> Ticket Danvil <danvil@…> Tue, 02 Oct 2012 22:31:04 GMT https://svn.boost.org/trac10/ticket/7462#comment:2 https://svn.boost.org/trac10/ticket/7462#comment:2 <ul> <li><strong>status</strong> <span class="trac-field-old">new</span> → <span class="trac-field-new">closed</span> </li> <li><strong>resolution</strong> → <span class="trac-field-new">fixed</span> </li> </ul> <p> (In <a class="changeset" href="https://svn.boost.org/trac10/changeset/83481" title="[geometry] Fix ticket 7462, degenerate union for float. This was ...">[83481]</a>) [geometry] Fix ticket 7462, degenerate union for float. This was caused by two distances being wrong (by floating point precision). We now use earlier the alternative sort method (sorting on left/right), using relaxed_epsilon. This fixes the cause. </p> Ticket Barend Gehrels Sun, 17 Mar 2013 21:31:23 GMT