DMSwarmProjectFields#

Project a set of swarm fields onto the cell DM

Synopsis#

#include "petscdmswarm.h"   
PETSC_EXTERN PetscErrorCode DMSwarmProjectFields(DM dm, PetscInt nfields, const char *fieldnames[], Vec **fields, PetscBool reuse)

Collective

Input parameters#

dm - the DMSWARM
nfields - the number of swarm fields to project
fieldnames - the textual names of the swarm fields to project
fields - an array of Vec’s of length nfields
reuse - flag indicating whether the array and contents of fields should be re-used or internally allocated

Notes#

Currently, the only available projection method consists of

     phi_i = \sum_{p=0}^{np} N_i(x_p) phi_p dJ / \sum_{p=0}^{np} N_i(x_p) dJ
   where phi_p is the swarm field at point p,
     N_i() is the cell DM basis function at vertex i,
     dJ is the determinant of the cell Jacobian and
     phi_i is the projected vertex value of the field phi.

If reuse is PETSC_FALSE, this function will allocate the array of Vec’s, and each individual Vec. The user is responsible for destroying both the array and the individual Vec objects.

Only swarm fields registered with data type of PETSC_REAL can be projected onto the cell DM.

Only swarm fields of block size = 1 can currently be projected.

The only projection methods currently only support the DMDA (2D) and DMPLEX (triangles 2D).