Hi Steve, Thank for your reply.
> On 30 Sep 2016, at 02:15, Stephen DeWitt <[email protected]> wrote: > > Hi Denis, > I'm sure there is someone more knowledgable than me, but I'll take a crack at > a couple of these: > > (2/3) Maybe I'm misunderstanding your circumstances, but if all you need is > different update flags for different fields you can do that with a single > MatrixFree object, but set different flags for each field with the > FEEvaluation::evaluate method > <https://dealii.org/8.4.0/doxygen/deal.II/classFEEvaluation.html#acc376d2cc45d850a86f5b76a39ec50de>. > I'm not quite sure what you mean with regards to solving a problem in a > staggered way, so you maybe you do actually need multiple MatrixFree objects. that would suggest that I keep one MatrixFree object for all linear operators. Say if I have mass matrix and Laplace matrix, i would then use update_values | update_gradients | update_JxW_values; in AdditionalData. But I wonder would that be any slower than two separate MatrixFree data’s, one with update_values | update_JxW_values; and one with update_gradients | update_JxW_values; ? You are right that we actually specify what to evaluate with FEEvaluation::evaluate(), so maybe in for update_values vs update_gradients it won’t be slower. However, i would still need to evaluate (once!) some functions at quadrature points, so I need a MatrixFree data with update_quadrature_points <https://www.dealii.org/developer/doxygen/deal.II/group__feaccess.html#ggaa94b67d2fdcc390690c523f28019e52fad5c9ff886b9615349a5d04a6c782df4a> set in AdditionalData. This certainly looks like a waste to keep this flag assigned to linear operators as I would be applying them hundreds of times and would never use location of quadrature points in real space. Regards, Denis -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
