petsc-3.14.6 2021-03-30

PetscDSUpdateBoundary

Change a boundary condition for the model. The pointwise functions are used to provide boundary values for essential boundary conditions. In FEM, they are acting upon by dual basis functionals to generate FEM coefficients which are fixed. Natural boundary conditions signal to PETSc that boundary integrals should be performaed, using the kernels from PetscDSSetBdResidual().

Synopsis

#include "petscds.h" 
PetscErrorCode PetscDSUpdateBoundary(PetscDS ds, PetscInt bd, DMBoundaryConditionType type, const char name[], const char labelname[], PetscInt field, PetscInt numcomps, const PetscInt *comps, void (*bcFunc)(void), void (*bcFunc_t)(void), PetscInt numids, const PetscInt *ids, void *ctx)

Input Parameters

	ds	- The PetscDS object
	bd	- The boundary condition number
	type	- The type of condition, e.g. DM_BC_ESSENTIAL/DM_BC_ESSENTIAL_FIELD (Dirichlet), or DM_BC_NATURAL (Neumann)
	name	- The BC name
	labelname	- The label defining constrained points
	field	- The field to constrain
	numcomps	- The number of constrained field components
	comps	- An array of constrained component numbers
	bcFunc	- A pointwise function giving boundary values
	bcFunc_t	- A pointwise function giving the time derviative of the boundary values, or NULL
	numids	- The number of DMLabel ids for constrained points
	ids	- An array of ids for constrained points
	ctx	- An optional user context for bcFunc

Note

The boundary condition number is the order in which it was registered. The user can get the number of boundary conditions from PetscDSGetNumBoundary(). See PetscDSAddBoundary() for a description of the calling sequences for the callbacks.

Level

developer

Location