From 07f2406dc196ce6b863aebad59018edd3bbae552 Mon Sep 17 00:00:00 2001 From: Benoit Jacob Date: Wed, 24 Nov 2010 08:23:17 -0500 Subject: [PATCH] some dox tweaks --- doc/C02_TutorialMatrixArithmetic.dox | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/doc/C02_TutorialMatrixArithmetic.dox b/doc/C02_TutorialMatrixArithmetic.dox index ae2964a46..b04821a87 100644 --- a/doc/C02_TutorialMatrixArithmetic.dox +++ b/doc/C02_TutorialMatrixArithmetic.dox @@ -102,7 +102,7 @@ The transpose \f$ a^T \f$, conjugate \f$ \bar{a} \f$, and adjoint (i.e., conjuga \verbinclude tut_arithmetic_transpose_conjugate.out -For real matrices, \c conjugate() is a no-operation, and so \c adjoint() is 100% equivalent to \c transpose(). +For real matrices, \c conjugate() is a no-operation, and so \c adjoint() is equivalent to \c transpose(). As for basic arithmetic operators, \c transpose() and \c adjoint() simply return a proxy object without doing the actual transposition. If you do b = a.transpose(), then the transpose is evaluated at the same time as the result is written into \c b. However, there is a complication here. If you do a = a.transpose(), then Eigen starts writing the result into \c a before the evaluation of the transpose is finished. Therefore, the instruction a = a.transpose() does not replace \c a with its transpose, as one would expect: @@ -155,13 +155,13 @@ If you know your matrix product can be safely evaluated into the destination mat \code c.noalias() += a * b; \endcode -For more details on this topic, see \ref TopicEigenExpressionTemplates "this page". +For more details on this topic, see the page on \ref TopicAliasing "aliasing". \b Note: for BLAS users worried about performance, expressions such as c.noalias() -= 2 * a.adjoint() * b; are fully optimized and trigger a single gemm-like function call. \section TutorialArithmeticDotAndCross Dot product and cross product -The above-discussed \c operator* cannot be used to compute dot and cross products directly. For that, you need the \link MatrixBase::dot() dot()\endlink and \link MatrixBase::cross() cross()\endlink methods. +For dot product and cross product, you need the \link MatrixBase::dot() dot()\endlink and \link MatrixBase::cross() cross()\endlink methods. Of course, the dot product can also be obtained as a 1x1 matrix as u.adjoint()*v.
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