From bd70c0090d047476be3bf7590d3aa24be5f9d0aa Mon Sep 17 00:00:00 2001 From: bangerth Date: Tue, 2 Aug 2011 14:50:13 +0000 Subject: [PATCH] Clarify documentation. git-svn-id: https://svn.dealii.org/trunk@23995 0785d39b-7218-0410-832d-ea1e28bc413d --- deal.II/include/deal.II/fe/fe_nedelec.h | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/deal.II/include/deal.II/fe/fe_nedelec.h b/deal.II/include/deal.II/fe/fe_nedelec.h index 50aaf77af9..87af364b17 100644 --- a/deal.II/include/deal.II/fe/fe_nedelec.h +++ b/deal.II/include/deal.II/fe/fe_nedelec.h @@ -101,20 +101,19 @@ template class MappingQ; * drop this first term. * * What this means for the present case: first the computation of - * gradients of Nedelec shape functions is wrong. Second, you will not - * notice this usually, for two reasons: + * gradients of Nedelec shape functions is wrong in general. Second, + * in the following two cases you will not notice this: * - * The first reason is that the gradient of the Jacobian vanishes if - * the cells are mapped by an affine mapping, to which the usual - * bilinear mapping reduces if the cell is a parallelogram. Then the - * gradient of the shape functions is computed exact, since the first - * term is zero. + * - If the cell is a parallelogram, then the usual bi-/trilinear mapping + * is in fact affine. In that case, the gradient of the Jacobian vanishes + * and the gradient of the shape functions is computed exactly, since the + * first term is zero. * - * Second, with the Nedelec elements, you will usually want to compute - * the curl, and extract and sum up the respective elements of the - * full gradient tensor. However, the curl of the Jacobian vanishes, - * so for the curl of shape functions the first term is irrelevant, - * and the curl will be computed correctly as well. + * - With the Nedelec elements, you will usually want to compute + * the curl, not the general derivative tensor. However, the curl of the + * Jacobian vanishes, so for the curl of shape functions the first term + * is irrelevant, and the curl will always be computed correctly even on + * cells that are not parallelograms. * * *

Interpolation

@@ -160,7 +159,7 @@ class FE_Nedelec : public FE_PolyTensor, dim> * element of degree @p p. */ FE_Nedelec (const unsigned int p); - + /** * Return a string that uniquely * identifies a finite -- 2.39.5