https://svn.boost.org/trac10/ticket/8434 <p> I was trying to use Sloan ordering to reduce the bandwidth on a couple of my finite element meshes. It did not give very good results; the bandwidth after reordering was exactly equal to number of vertexes! So, I tried the example program here: <a href="http://www.boost.org/doc/libs/1_53_0/libs/graph/example/sloan_ordering.cpp">http://www.boost.org/doc/libs/1_53_0/libs/graph/example/sloan_ordering.cpp</a> I expected the results given in the comments in the example file: </p> <pre class="wiki">/* Sample Output ##################################### ### First light of sloan-ordering ### ##################################### original bandwidth: 8 original profile: 42 original max_wavefront: 7 original aver_wavefront: 4.2 original rms_wavefront: 4.58258 Starting vertex: 0 Pseudoperipheral vertex: 9 Pseudoperipheral radius: 4 Sloan ordering starting at: 0 0 8 3 7 5 2 4 6 1 9 bandwidth: 4 profile: 28 max_wavefront: 4 aver_wavefront: 2.8 rms_wavefront: 2.93258 Sloan ordering without a start-vertex: 8 0 3 7 5 2 4 6 1 9 bandwidth: 4 profile: 27 max_wavefront: 4 aver_wavefront: 2.7 rms_wavefront: 2.84605 ############################### ### sloan-ordering finished ### ############################### */ </pre><p> Instead I got: </p> <pre class="wiki">##################################### ### First light of sloan-ordering ### ##################################### original bandwidth: 8 original profile: 58 original max_wavefront: 7 original aver_wavefront: 4.2 original rms_wavefront: 4.58258 Starting vertex: 0 Pseudoperipheral vertex: 9 Pseudoperipheral radius: 4 Sloan ordering starting at: 0 0 7 4 9 1 6 2 5 3 8 bandwidth: 8 profile: 55 max_wavefront: 6 aver_wavefront: 3.6 rms_wavefront: 3.94968 Sloan ordering without a start-vertex: 8 5 4 9 1 7 6 2 0 3 bandwidth: 9 profile: 66 max_wavefront: 7 aver_wavefront: 4.2 rms_wavefront: 4.66905 ############################### ### sloan-ordering finished ### ############################### </pre><p> You can see that the current results are in line with what I was experiencing with my own meshes, namely, no reduction in bandwidth or profile. </p> <p> Sloan ordering seems to have first appeared in boost 1.30.0. I tried that version too, and it gives essentially the same results as I see with 1.53. So, perhaps it's the comments in the example program that need to be updated and Sloan ordering is not appropriate for my meshes. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/8434 Trac 1.4.3 Jeremiah Willcock Sat, 13 Apr 2013 18:20:18 GMT https://svn.boost.org/trac10/ticket/8434#comment:1 https://svn.boost.org/trac10/ticket/8434#comment:1 <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/83877" title="Fixed 32/64-bit size issues; fixes #8434">[83877]</a>) Fixed 32/64-bit size issues; fixes <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/8434" title="#8434: Bugs: Sloan Ordering Gives Incorrect Results (closed: fixed)">#8434</a> </p> Ticket