interpoalate just evaluates the function at support points of FE basis (assuming that you have one with support points) and sets those values to DoFs, whereas project (as the name implies) does L2 projection. Thus as others have mentioned you are solving Mx = U where M is the mass matrix.
Regards, Denis. > On 16 Oct 2017, at 21:44, 'Maxi Miller' via deal.II User Group > <dealii@googlegroups.com> wrote: > > Yes, .interpolate() works fine. But what is the difference between > interpolate() and project()? > > Am Montag, 16. Oktober 2017 08:54:02 UTC+2 schrieb Denis Davydov: > Or you may want to use interpolate if this is enough > https://www.dealii.org/developer/doxygen/deal.II/namespaceVectorTools.html#a05db6c8cebf924b417dd92f525efe3db > > <https://www.dealii.org/developer/doxygen/deal.II/namespaceVectorTools.html#a05db6c8cebf924b417dd92f525efe3db> > > Regards, > Denis > > On Friday, October 13, 2017 at 11:05:01 AM UTC+2, Maxi Miller wrote: > I try to apply initial values to a vector defined as > LinearAlgebraTrilinos::MPI::Vector using > VectorTools::project (dof_handler, hanging_node_constraints, > QGauss<dim>(fe.degree+1), > InitialValues<dim>(), > local_solution); > > > When initializing the variable fe (as FESystem<dim>) with one or two > components, it works fine. For more than two components I get the error > -------------------------------------------------------- > An error occurred in line <1366> of file > <~/Downloads/dealii/include/deal.II/numerics/vector_tools.templates.h> in > function > void dealii::VectorTools::{anonymous}::project(const > dealii::Mapping<dim>&, const dealii::DoFHandler<dim>&, const > dealii::ConstraintMatrix&, const dealii::Quadrature<dim>&, const > dealii::Function<dim, typename VectorType::value_type>&, VectorType&, bool, > const dealii > ::Quadrature<(dim - 1)>&, bool) [with VectorType = > dealii::TrilinosWrappers::MPI::Vector; int dim = 2; typename > VectorType::value_type = double] > The violated condition was: > (dynamic_cast<const parallel::Triangulation<dim>* > > (&(dof.get_triangulation()))==nullptr) > Additional information: > You are trying to use functionality in deal.II that is currently not > implemented. In many cases, this indicates that there simply didn't appear > much of a need for it, or that the author of the original code did not have > the time to implement a particular case. If you > hit this exception, it is therefore worth the time to look into the code to > find out whether you may be able to implement the missing functionality. If > you do, please consider providing a patch to the deal.II development sources > (see the deal.II website on how to contri > bute). > > Stacktrace: > ----------- > #0 /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre: > #1 /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre: void > dealii::VectorTools::project<2, dealii::TrilinosWrappers::MPI::Vector, > 2>(dealii::DoFHandler<2, 2> const&, dealii::ConstraintMatrix const&, > dealii::Quadrature<2> const&, dealii::Function<2, > dealii::TrilinosWrappers::MPI > ::Vector::value_type> const&, dealii::TrilinosWrappers::MPI::Vector&, bool, > dealii::Quadrature<(2)-(1)> const&, bool) > #2 ./main: Step15::MinimalSurfaceProblem<2>::run() > #3 ./main: main > -------------------------------------------------------- > > [linux-lb8c:15830] *** Process received signal *** > [linux-lb8c:15830] Signal: Aborted (6) > [linux-lb8c:15830] Signal code: (-6) > [linux-lb8c:15830] [ 0] /lib64/libpthread.so.0(+0x12270)[0x7f294a477270] > [linux-lb8c:15830] [ 1] /lib64/libc.so.6(gsignal+0x110)[0x7f2946c1f0d0] > [linux-lb8c:15830] [ 2] /lib64/libc.so.6(abort+0x151)[0x7f2946c206b1] > [linux-lb8c:15830] [ 3] > /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre(+0x6b9e5d1)[0x7f295b49e5d1] > [linux-lb8c:15830] [ 4] > /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre(_ZN6dealii18deal_II_exceptions9internals5abortERKNS_13ExceptionBaseE+0x1a)[0x7f295b49edaf] > > [linux-lb8c:15830] [ 5] > /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre(_ZN6dealii18deal_II_exceptions9internals11issue_errorINS_18StandardExceptions17ExcNotImplementedEEEvNS1_17ExceptionHandlingEPKciS7_S7_S7_T_+0x98)[0x7f2957373ea1] > > [linux-lb8c:15830] [ 6] > /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre(+0x3f38e23)[0x7f2958838e23] > [linux-lb8c:15830] [ 7] > /opt/dealII/lib/libdeal_II.g.so.9.0.0-pre(_ZN6dealii11VectorTools7projectILi2ENS_16TrilinosWrappers3MPI6VectorELi2EEEvRKNS_10DoFHandlerIXT_EXT1_EEERKNS_16ConstraintMatrixERKNS_10QuadratureIXT_EEERKNS_8FunctionIXT1_ENT0_10value_typeEEERSH_bRKNSC_IX > miT_Li1EEEEb+0x2f)[0x7f295894906e] > [linux-lb8c:15830] [ 8] > ./main(_ZN6Step1521MinimalSurfaceProblemILi2EE3runEv+0xc08)[0x420d08] > [linux-lb8c:15830] [ 9] ./main(main+0x3c)[0x414ad0] > [linux-lb8c:15830] [10] > /lib64/libc.so.6(__libc_start_main+0xea)[0x7f2946c09f4a] > [linux-lb8c:15830] [11] ./main(_start+0x2a)[0x41477a] > [linux-lb8c:15830] *** End of error message *** > Abgebrochen (Speicherabzug geschrieben) > > when running in debug mode. It runs fine in release mode. Why does that > happen for more than two components, and how can I fix/circumvent that? Or > did I (again) forget something? > My minimal example is attached, the behaviour happens when setting > NUM_COMPONENTS via > #define NUM_COMPONENTS 100 > > to a value larger than 2. > > Thank you! > > > -- > The deal.II project is located at http://www.dealii.org/ > <http://www.dealii.org/> > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > <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/4YoJZ8d2-XM/unsubscribe > <https://groups.google.com/d/topic/dealii/4YoJZ8d2-XM/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > dealii+unsubscr...@googlegroups.com > <mailto:dealii+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- 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. For more options, visit https://groups.google.com/d/optout.
