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Diffstat (limited to 'doc/PreprocessorDirectives.dox')
| -rw-r--r-- | doc/PreprocessorDirectives.dox | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/doc/PreprocessorDirectives.dox b/doc/PreprocessorDirectives.dox index e67991fb7..4be2167ef 100644 --- a/doc/PreprocessorDirectives.dox +++ b/doc/PreprocessorDirectives.dox @@ -27,10 +27,23 @@ are doing. Defaults to the %IOFormat constructed by the default constructor IOFormat::IOFormat(). - \b EIGEN_INITIALIZE_MATRICES_BY_ZERO - if defined, all entries of newly constructed matrices and arrays are initialized to zero, as are new entries in matrices and arrays after resizing. Not defined by default. + \warning The unary (resp. binary) constructor of \c 1x1 (resp. \c 2x1 or \c 1x2) fixed size matrices is + always interpreted as an initialization constructor where the argument(s) are the coefficient values + and not the sizes. For instance, \code Vector2d v(2,1); \endcode will create a vector with coeficients [2,1], + and \b not a \c 2x1 vector initialized with zeros (i.e., [0,0]). If such cases might occur, then it is + recommended to use the default constructor with a explicit call to resize: + \code + Matrix<?,SizeAtCompileTime,1> v; + v.resize(size); + Matrix<?,RowsAtCompileTime,ColsAtCompileTime> m; + m.resize(rows,cols); + \endcode - \b EIGEN_INITIALIZE_MATRICES_BY_NAN - if defined, all entries of newly constructed matrices and arrays are initialized to NaN, as are new entries in matrices and arrays after resizing. This option is especially useful for debugging purpose, though a memory tool like <a href="http://valgrind.org/">valgrind</a> is preferable. Not defined by default. + \warning See the documentation of \c EIGEN_INITIALIZE_MATRICES_BY_ZERO for a discussion on a limitations + of these macros when applied to \c 1x1, \c 1x2, and \c 2x1 fixed-size matrices. - \b EIGEN_NO_AUTOMATIC_RESIZING - if defined, the matrices (or arrays) on both sides of an assignment <tt>a = b</tt> have to be of the same size; otherwise, %Eigen automatically resizes \c a so that it is of the correct size. Not defined by default. @@ -61,6 +74,8 @@ run time. However, these assertions do cost time and can thus be turned off. expect that any objects passed to it are aligned. This will turn off vectorization. Not defined by default. - \b EIGEN_DONT_ALIGN_STATICALLY - disables alignment of arrays on the stack. Not defined by default, unless \c EIGEN_DONT_ALIGN is defined. + - \b EIGEN_DONT_PARALLELIZE - if defined, this disables multi-threading. This is only relevant if you enabled OpenMP. + See \ref TopicMultiThreading for details. - \b EIGEN_DONT_VECTORIZE - disables explicit vectorization when defined. Not defined by default, unless alignment is disabled by %Eigen's platform test or the user defining \c EIGEN_DONT_ALIGN. - \b EIGEN_FAST_MATH - enables some optimizations which might affect the accuracy of the result. This currently |