From: Wolfgang Bangerth Date: Thu, 29 Mar 2018 22:24:51 +0000 (-0600) Subject: Update a comment to explain what is going to happen. X-Git-Tag: v9.0.0-rc1~200^2~2 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c64335b538024d5a227adb4084b0d737ae4a2b27;p=dealii.git Update a comment to explain what is going to happen. --- diff --git a/include/deal.II/fe/fe_poly_face.templates.h b/include/deal.II/fe/fe_poly_face.templates.h index 3499b6c16a..9a30f3fbcd 100644 --- a/include/deal.II/fe/fe_poly_face.templates.h +++ b/include/deal.II/fe/fe_poly_face.templates.h @@ -83,8 +83,17 @@ fill_fe_values (const typename Triangulation::cell_iterator &, const typename FiniteElement::InternalDataBase &, dealii::internal::FEValuesImplementation::FiniteElementRelatedData &) const { - // Do nothing, since we do not have - // values in the interior + // Do nothing, since we do not have values in the interior. Since + // FEValues initializes the output variables for this function + // with invalid values, this means that we simply leave them at + // the invalid values -- typically, signaling NaNs. This means + // that when you later look at those components of shape + // functions or solution vectors that correspond to the + // face element, you will see signaling_NaNs. This simply means + // that you should not use them -- the shape functions and the + // solution do not actually live inside the cell, and so any + // attempt at evaluating it there *should* yield an invalid + // result. }