petsc-3.8.4 2018-03-24

PetscDSGetResidual

Get the pointwise residual function for a given test field

Synopsis

#include "petscds.h" 
PetscErrorCode PetscDSGetResidual(PetscDS prob, PetscInt f,
                                  void (**f0)(PetscInt dim, PetscInt Nf, PetscInt NfAux,
                                              const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
                                              const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
                                              PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[]),
                                  void (**f1)(PetscInt dim, PetscInt Nf, PetscInt NfAux,
                                              const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
                                              const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
                                              PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f1[]))

Not collective

Input Parameters

	prob	- The PetscDS
	f	- The test field number

Output Parameters

	f0	- integrand for the test function term
	f1	- integrand for the test function gradient term

Note: We are using a first order FEM model for the weak form

\int_\Omega \phi f_0(u, u_t, \nabla u, x, t) + \nabla\phi \cdot {\vec f}_1(u, u_t, \nabla u, x, t)

The calling sequence for the callbacks f0 and f1 is given by

f0(PetscInt dim, PetscInt Nf, PetscInt NfAux,

   const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],

   const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],

   PetscReal t, const PetscReal x[], PetscScalar f0[])

	dim	- the spatial dimension
	Nf	- the number of fields
	uOff	- the offset into u[] and u_t[] for each field
	uOff_x	- the offset into u_x[] for each field
	u	- each field evaluated at the current point
	u_t	- the time derivative of each field evaluated at the current point
	u_x	- the gradient of each field evaluated at the current point
	aOff	- the offset into a[] and a_t[] for each auxiliary field
	aOff_x	- the offset into a_x[] for each auxiliary field
	a	- each auxiliary field evaluated at the current point
	a_t	- the time derivative of each auxiliary field evaluated at the current point
	a_x	- the gradient of auxiliary each field evaluated at the current point
	t	- current time
	x	- coordinates of the current point
	numConstants	- number of constant parameters
	constants	- constant parameters
	f0	- output values at the current point

PetscDSGetResidual

Synopsis

Input Parameters

Output Parameters

Note: We are using a first order FEM model for the weak form

The calling sequence for the callbacks f0 and f1 is given by

See Also