dmda_repart.h

#ifndef DMDA_REPART_INCLUDED
#define DMDA_REPART_INCLUDED

#include <petscdmda.h>

/** Repartitioning of a Petsc DMDA.
 *
 * Creates a new DMDA and a new global vector based on the
 * old DMDA and the old global vector and replaces
 * the old ones with them.
 *
 * The ownership range of the new da is given by lx, ly and lz.
 *
 * This function copies the ApplicationContext and the Field
 * Names from the old to the new, repartitioned da.
 *
 * Note: Reset TS, SNES, etc. afterwards!
 * Also call any additional setters that were called on the
 * original DM.
 *
 * @param da Pointer to the DMDA to be replaced
 * @param X Pointer to the Vec to be replaced
 * @param lx Number of nodes per process in x direction
 * @param ly Number of nodes per process in y direction
 * @param lz Number of nodes per process in z direction
 * @param setFromOptions Set this to PETSC_TRUE if DMSetFromOptions should
 *                       be called on the newly created DMDA
 */
PetscErrorCode
DMDA_repart(DM* da, Vec *X, PetscInt lx[], PetscInt ly[], PetscInt lz[],
            PetscBool setFromOptions);


/****************************************************************************/
/* The following functions are for repartitioning more than one associated  */
/* global Vec. They all perform the same task but their interface is        */
/* different. Use whatever fits the data layout in your program most.       */
/****************************************************************************/

/** Repartitions a Petsc DMDA and "nvec" associated global Vec provided as
 * array "X" of Vec.
 * Use this if you organize your vectors in an array. Do not use it in
 * conjunction with a compound literal. Use DMDA_repart(l|n) instead.
 *
 * @see DMDA_repart
 */
PetscErrorCode
DMDA_repartv(DM* da, PetscInt lx[], PetscInt ly[], PetscInt lz[],
              PetscBool setFromOptions, PetscInt nvec, Vec X[]);

/** Repartitions a Petsc DMDA and associated global Vecs provided as va_args.
 * The last parameter in a call to this function *must* be "(Vec*) NULL".
 * I.e. "DMDA_repartl(da, lx, ly, lz, PETSC_FALSE, &X, (Vec*) NULL);"
 * is equivalent to "DMDA_repart(da, &X, lx, ly, lz, PETSC_FALSE);"
 *
 * @see DMDA_repart
 */
PetscErrorCode
DMDA_repartl(DM* da, PetscInt lx[], PetscInt ly[], PetscInt lz[],
              PetscBool setFromOptions, Vec *X, ...);

/** Determine new ownership ranges for repartitioning.
 *
 * Supply NULL as "lz" if operating on a 2D DMDA and also additionally
 * "ly" for 1D DMDAs.
 * Other than for usage with 1D or 2D DMDAs, neither, lx, ly nor lz are allowed
 * to be NULL.
 *
 * @param da DMDA
 * @param W global Vec of weights for each cell
 * @param lx Number of cells per process in x-direction (out)
 * @param ly Number of cells per process in y-direction (out), possibly NULL
 * @param lz Number of cells per process in z-direction (out), possibly NULL
 * @param grid_min Minimum number of grid points for each partition in every direction
 *                 (or 0 if you don't care)
 */
PetscErrorCode
DMDA_repart_ownership_ranges(DM da, Vec W,
                             PetscInt lx[], PetscInt ly[], PetscInt lz[],
                             PetscInt grid_min);

#endif