DMFieldEvaluateFV#

Evaluate the mean of a field and its finite volume derivatives on a set of points.

Synopsis#

#include "petscdmfield.h" 
#include "petscdmfield.h" 
PetscErrorCode DMFieldEvaluateFV(DMField field, IS cellIS, PetscDataType datatype, void *B, void *D, void *H)

Not Collective

Input Parameters#

field - The DMField object
cellIS - Index set for cells on which to evaluate the field
datatype - The PetscDataType of the output arrays: either PETSC_REAL or PETSC_SCALAR. If the field is complex and datatype is PETSC_REAL, the real part of the field is returned.

Output Parameters#

B - pointer to data of size c * n * sizeof(datatype), where c is the number of components in the field. If B is not NULL, the values of the field are written in this array, varying first by component, then by point.
D - pointer to data of size d * c * n * sizeof(datatype). If D is not NULL, the values of the field’s spatial derivatives are written in this array, varying first by the partial derivative component, then by field component, then by point.
H - pointer to data of size d * d * c * n * sizeof(datatype). If H is not NULL, the values of the field’s second spatial derivatives are written in this array, varying first by the second partial derivative component, then by field component, then by point.