Boost C++ Libraries: Ticket #2800: Bug in transposed_structure https://svn.boost.org/trac10/ticket/2800 <p> The transposed_structure template simply takes an upper triangular matrix and regards it as the transpose of a lower triangular matrix. It doesn't take into account the row/column major storage, leading to the following bug: </p> <p> If we take the upper matrix U </p> <p> 1 2 3 </p> <ul><li>4 5 </li><li>- 6 </li></ul><p> and regard it as the transpose of a lower matrix L </p> <p> 1 2 4 3 5 6 </p> <p> without a row/column major swap, then storing the row major version of the lower matrix is the same as storing the column major version of the upper matrix: </p> <p> a) row_major for U: 1 2 3 4 5 6 b) row_major for L: 1 2 4 3 5 6 </p> <p> Since the transposed_structure template simply maps the elements to the transpose and doesn't change the storage, we are in fact storing b) instead of a). </p> en-us Boost C++ Libraries /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/2800 Trac 1.4.3 anonymous Wed, 25 Feb 2009 20:03:01 GMT attachment set https://svn.boost.org/trac10/ticket/2800 https://svn.boost.org/trac10/ticket/2800 <ul> <li><strong>attachment</strong> → <span class="trac-field-new">main.cpp</span> </li> </ul> <p> C++ test file for triangular matrix storage schemes </p> Ticket anonymous Wed, 25 Feb 2009 20:07:11 GMT <link>https://svn.boost.org/trac10/ticket/2800#comment:1 </link> <guid isPermaLink="false">https://svn.boost.org/trac10/ticket/2800#comment:1</guid> <description> <p> The matrices above got flattened into the same line. The example above should read: </p> <p> upper matrix U <br /> </p> <p> 1 2 3<br /> </p> <ul><li>4 5<br /> </li><li>- 6 </li></ul><p> lower matrix L <br /> </p> <p> 1<br /> 2 4<br /> 3 5 6<br /> </p> <p> and the row major versions for U and L, respectively<br /> </p> <p> a) row_major for U: 1 2 3 4 5 6 <br /> b) row_major for L: 1 2 4 3 5 6 </p> </description> <category>Ticket</category> </item> <item> <dc:creator>Gunter</dc:creator> <pubDate>Fri, 13 Mar 2009 21:07:17 GMT</pubDate> <title>status changed; resolution set https://svn.boost.org/trac10/ticket/2800#comment:2 https://svn.boost.org/trac10/ticket/2800#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/51764" title="functional.hpp: * added triangular_type definitions * added ...">[51764]</a>) functional.hpp: </p> <ul><li>added triangular_type definitions </li><li>added transposed_layout to basic_row_major and basic_column_major </li><li>fix <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/2800" title="#2800: Bugs: Bug in transposed_structure (closed: fixed)">#2800</a> : transposed_structure has to switch row major and column major </li></ul> Ticket Gunter Thu, 02 Apr 2009 22:15:12 GMT <link>https://svn.boost.org/trac10/ticket/2800#comment:3 </link> <guid isPermaLink="false">https://svn.boost.org/trac10/ticket/2800#comment:3</guid> <description> <p> (In <a class="changeset" href="https://svn.boost.org/trac10/changeset/52145" title="ublas/expression_types.hpp: added typedef ublas_expression::self_type ...">[52145]</a>) ublas/expression_types.hpp: added typedef ublas_expression::self_type ublas/fwd.hpp: added default template arguments to declaration of generalized_vector_of_vector ublas/lu.hpp: added constructor from vector to permutation_matrix ublas/storage.hpp: fix <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/2891" title="#2891: Bugs: BOOST_UBLAS_CHECK checking the wrong variable (closed: fixed)">#2891</a> ublas/detail/concepts.hpp: added documentation and some missing concept checks </p> <p> ublas/traits.hpp: </p> <blockquote> <p> added new traits classes: container_traits, matrix_traits, vector_traits they work for all ublas classes and c-arrays (T[M][N] and T[M]) </p> </blockquote> <p> ublas/functional.hpp: </p> <blockquote> <p> added triangular type tags fix <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/2800" title="#2800: Bugs: Bug in transposed_structure (closed: fixed)">#2800</a> added my name to copyright message </p> </blockquote> </description> <category>Ticket</category> </item> </channel> </rss>