[petsc-users] Fwd: Inquiry about the dual space (PetscFECreateTabulation_Basic)

[neil liu]

Hello, Petsc group,

I am learning the FE structure in Petsc by running case
https://petsc.org/main/src/snes/tutorials/ex12.c.html with -run_type test
-bc_type dirichlet -dm_plex_interpolate 0 -petscspace_degree 1
-show_initial -dm_plex_print_fem 1

When I check the subroutine PetscFECreateTabulation_Basic, I can not
understand some parameters there.

For the following lines in the file (
https://petsc.org/release//src/dm/dt/fe/impls/basic/febasic.c.html#PETSCFEBASIC
)

135:   PetscCall
<https://petsc.org/release//manualpages/Sys/PetscCall/>(PetscDualSpaceGetDimension
<https://petsc.org/release//manualpages/DUALSPACE/PetscDualSpaceGetDimension/>(fem->dualSpace,
&pdim));136:   PetscCall
<https://petsc.org/release//manualpages/Sys/PetscCall/>(PetscFEGetNumComponents
<https://petsc.org/release//manualpages/FE/PetscFEGetNumComponents/>(fem,
&Nc));

Here, Nc = 2, pdim =6. I am running a scalar case with degree of 1,

I expect Nc = 1 and pdim =3. Could you please explain this? In addition,

Thanks,

Xiaodong
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