Assemble bilinearform in the case of VectorFECurlIntegrator

[Asadanees]

ND_FECollection fe_coll(order,dim);
FiniteElementSpace fespace(mesh, &fe_coll);

S.AddDomainIntegrator(new VectorFECurlIntegrator);
Problem S is not assemble below command

1. S.Assemble(skip_zero_entries);

The error message is
DenseMatrix::operator() const
Aborted (core dumped)
The detail of error is
#0 0xb7fdd428 in __kernel_vsyscall ()
#1 0xb7cf1687 in __GI_raise (sig=sig@entry=6)

at ../nptl/sysdeps/unix/sysv/linux/raise.c:56

#2 0xb7cf4ab3 in __GI_abort () at abort.c:89
#3 0x08053d36 in mfem::mfem_error (

msg=0x816775b "DenseMatrix::operator() const") at error.cpp:34

#4 0x08064fe8 in mfem::DenseMatrix::operator() (this=0xbfffd32c, i=0, j=0)

at densemat.hpp:631

#5 0x08079d0a in mfem::SparseMatrix::AddSubMatrix (this=0x81f5f20, rows=...,

cols=..., subm=..., skip_zeros=0) at sparsemat.cpp:1754

#6 0x080e417c in mfem::BilinearForm::Assemble (this=0xbfffd704, skip_zeros=0)

at bilinearform.cpp:295

#7 0x0804cb59 in MaxwellOperator::MaxwellOperator (this=0xbfffd65c, f=...,

ess_bdr=...) at ex17.cpp:660

#8 0x0804ba3c in main (argc=1, argv=0xbffff054) at ex17.cpp:389

Please help me to fix the error
Thanks in advance

[v-dobrev]

Hi,

The VectorFECurlIntegrator is only meant to be used with different trial and test spaces: the trial space should use Nedelec elements and the test space should use Raviart-Thomas elements. In particular, this means that instead of BilinearForm (which uses that same trial and test spaces) you need to use MixedBilinearForm where the trail and the test spaces are different.

Regards,
Veselin

[Asadanees]

Dear Dobrev,
Thanks for your cooperation.
Best wishes.
Sincerely yours,
Asad Anees