PetscDSGetObjective — PETSc 3.23.0 documentation

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# PetscDSGetObjective

Get the pointwise objective function for a given test field

## Synopsis

    #include "petscds.h"
    PetscErrorCode PetscDSGetObjective(PetscDS ds, PetscInt f, void (**obj)(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 obj[]))

Not Collective

## Input Parameters

- ds - The `PetscDS`

- f - The test field number

## Output Parameter

- obj - integrand for the test function term

## Calling sequence of `obj`

- dim - the coordinate dimension

- Nf - the number of fields

- NfAux - the number of auxiliary 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

- obj - output values at the current point

## Note

We are using a first order FEM model for the weak form: \( \int_\Omega \phi\,\mathrm{obj}(u, u_t, \nabla u, x, t)\)

## See Also

`PetscDS`, `PetscDSSetObjective()`, `PetscDSGetResidual()`

## Level

intermediate

## Location

src/dm/dt/interface/dtds.c

Index of all DT routines
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Index of all manual pages