PetscDSGetResidual#

Get the pointwise residual function for a given test field

Synopsis#

#include "petscds.h" 
PetscErrorCode PetscDSGetResidual(PetscDS ds, 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#

  • ds - The PetscDS

  • f - The test field number

Output Parameters#

  • f0 - integrand for the test function term

  • f1 - integrand for the test function gradient term

Calling sequence of f0 and f1#

  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[])

  • 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

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)

See Also#

PetscDS, PetscDSSetResidual()

Level#

intermediate

Location#

src/dm/dt/interface/dtds.c

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