Hi Wolfgang,
*> Are you running your program in debug mode? You should have gotten an error message with the code above.* I wasn't b/c it typically runs slower than release mode... Ok I just finished installing a debug version and it gives an error message. Wow, that would've really helped me solve this problem sooner. Thanks for the help, Chad On Sun, Oct 15, 2023 at 7:28 PM Wolfgang Bangerth <bange...@colostate.edu> wrote: > On 10/14/23 21:01, Chad wrote: > > > > dealii::VectorTools::interpolate_boundary_values(dof_handler, 1, > > dealii::Functions::ConstantFunction<dim>(1.0), boundary_values, > var1Mask); > > dealii::VectorTools::interpolate_boundary_values(dof_handler, 1, > > dealii::Functions::ConstantFunction<dim>(2.0), boundary_values, > var2Mask); > > > > Var1 displays the correct BC in the vtu file but Var2 displays results > as if a > > BC of 0.0 was used instead of 2.0. > > I am surprised this actually works. The boundary value function needs to > have > the same number of vector components as the finite element in use. Are you > running your program in debug mode? You should have gotten an error > message > with the code above. > > > The fix seems to be that you need to > > actually use: > > > > dealii::VectorTools::interpolate_boundary_values(dof_handler, 1, > > dealii::Functions::ConstantFunction<dim>(2.0, *X*), boundary_values, > var2Mask); > > > > where X >= (varIndex+1); i.e. 1 & 2 for var1 & var2 respectively. > Looking at > > the documentation for ConstantFunction > > < > https://www.dealii.org/current/doxygen/deal.II/classFunctions_1_1ConstantFunction.html#a97c9eeab728d22be4b3dddb351d8e754> > I'd assume that the default value of 1 along with the ComponentMask would > be sufficient to apply the BC since I only need a ConstantFunction of size > 1 and the ComponentMask would then determine which component(s) to apply > this value to. However, it appears you need a ConstantFunction with a size > of ComponentMask+1 so the mask can access the ConstantFunction component(s) > matching the ComponentMask(s). > > The general rule is that you need to pass function objects that have the > same > number of components as the finite element in question -- regardless of > whether or not you are only evaluating some of the components. That's > because > oftentimes you create function objects that will be used in a variety of > contexts (for boundary values of different kinds, computing the error, > evaluating error estimators, etc.) where sometimes you might apply a mask > and > othertimes you don't. > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bange...@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 a topic in the > Google Groups "deal.II User Group" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/dealii/XaO4TZYrhCQ/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > dealii+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/9f8d708a-053d-5ee3-eee1-d17380509a79%40colostate.edu > . > -- 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/CAJ93qFjRSmCYEGLdzRaOjrAYmDp7dJVQmXGc%3DzY-uuSvyYg-_A%40mail.gmail.com.
