From: bangerth Date: Fri, 30 Aug 2013 22:14:13 +0000 (+0000) Subject: Patch by Denis Davydov: Document what exactly the gradient of a vector is. X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12e3f6f99f8cad94ea303f7a7f388073b6fb9f17;p=dealii-svn.git Patch by Denis Davydov: Document what exactly the gradient of a vector is. git-svn-id: https://svn.dealii.org/trunk@30540 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/include/deal.II/fe/fe_values.h b/deal.II/include/deal.II/fe/fe_values.h index 1b0164b656..4963d54c30 100644 --- a/deal.II/include/deal.II/fe/fe_values.h +++ b/deal.II/include/deal.II/fe/fe_values.h @@ -440,6 +440,17 @@ namespace FEValuesViews * this class should not be used for this * context. * + * This class allows to query the + * value, gradient and divergence of + * (components of) shape functions + * and solutions representing + * vectors. The + * gradient of a vector + * $d_{k}, 0\le k<\text{dim}$ is + * defined as + * $S_{ij} = \frac{\partial d_{i}}{\partial x_j}, + * 0\le i,j<\text{dim}$. + * * You get an object of this type if you * apply a FEValuesExtractors::Vector to an * FEValues, FEFaceValues or @@ -467,6 +478,9 @@ namespace FEValuesViews * dim components of the * finite element, the gradient is a * Tensor@<2,spacedim@>. + * + * See the general documentation of this class for how exactly + * the gradient of a vector is defined. */ typedef dealii::Tensor<2,spacedim> gradient_type; @@ -647,6 +661,9 @@ namespace FEValuesViews * function and quadrature point * selected by the arguments. * + * See the general documentation of this class for how exactly + * the gradient of a vector is defined. + * * @note The meaning of the arguments * is as documented for the value() * function.