Lars,
> I am trying to implement and HDG like method from [1], but without the > elimination process described in step 51. Thereby creating a block matrix. > > To implement this I use as finite element a system of FE_DGQ + FE_FaceQ. > On the face I need to compute integrals between the functions from the > trace space (i.e., from FE_FaceQ) and the normal times gradient of the > functions inside the element (i.e., from FE_DGQ). Therefore, I pass > update_gradients to FE_FaceValues, but this runs into the exception that > the gradients are not implemented for FE_FaceQ. Note that the lack of > gradients of FE_FaceQ is no problem, as its gradients are not need and > (I expect) not well defined, but I do need the gradients of FE_DGQ. I see the problem. I *think* that the right approach would probably be to remove the assertion in the fill_fe_values function of FE_FaceQ that you see, and instead fill the fields that should be filled with the gradients with some kind of numbers::signaling_nan() -- in other words, make sure that it's allowed to call the function with update_gradient, but also ensure that you're poisoning the returned values with values that will trigger a floating point exception once anyone tries to use them. (It is conceivable that these memory locations are already pre-set to have these signaling nans in them.) Do you want to give this a try and see whether you can come up with a patch? Best W. -- ------------------------------------------------------------------------ Wolfgang Bangerth email: [email protected] www: http://www.math.colostate.edu/~bangerth/ -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/4b250c0d-b2a8-b0e5-19d7-aa31736aeac0%40colostate.edu.
