Dear Prof. Bangerth, Thank you. I checked this on my problem and it is working.
Regards, On Saturday, May 29, 2021 at 2:24:29 AM UTC+5:30 Wolfgang Bangerth wrote: > > Turiya, > > > I have just started in dealii and going through the tutorials to solve a > > Neumann boundary value problem. > > > > I have the following situation: the Neumann boundary data (say g) is > defined > > as a Function and the solution obtained by solving my pde is a > Vector<double> > > (say v). How do I take the L2 inner product of g and trace(v). How do I > get > > this inner product between a Function and a Vector <double>. > > > > I can find each face which is on the boundary and I can get the values > of g at > > all the > > quadrature points of the face and the JxW at those points. However, to > obtain the > > surface intergral, I also need the values of v at these quadrature > points. How > > can I get > > the values at the quadrature points of the solution v? > > Your inner product is, I assume, an integral over the boundary. Boundary > integrals are always computed via the FEFaceValues class, in the same way > as > integrals over cells are computed via the FEValues class. > > To get the solution values at quadrature points you would use the > FEFaceValues::get_function_values() function. This is no different than > what > FEValues::get_function_values() does for quadrature points on cells, which > is > something you can find in a number of tutorial programs (e.g., step-9, > step-21, or step-15's and step-19's use of the corresponding > get_function_gradients() function). > > Best > W. > > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bang...@colostate.edu > 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 dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/1b405d73-7fad-47be-8ed6-a1a65fb0800bn%40googlegroups.com.
