partition.c

/*******************************************************************************
 * This file is part of SWIFT.
 * Copyright (c) 2016 Peter W. Draper (p.w.draper@durham.ac.uk)
 *                    Pedro Gonnet (pedro.gonnet@durham.ac.uk)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/

/**
 *  @file partition.c
 *  @brief file of various techniques for partitioning and repartitioning
 *  a grid of cells into geometrically connected regions and distributing
 *  these around a number of MPI nodes.
 *
 *  Currently supported partitioning types: grid, vectorise and METIS.
 */

/* Config parameters. */
#include "../config.h"

/* Standard headers. */
#include <float.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>

/* MPI headers. */
#ifdef WITH_MPI
#include <mpi.h>
/* METIS headers only used when MPI is also available. */
#ifdef HAVE_METIS
#include <metis.h>
#endif
#endif

/* Local headers. */
#include "debug.h"
#include "engine.h"
#include "error.h"
#include "partition.h"
#include "restart.h"
#include "space.h"
#include "tools.h"

/* Maximum weight used for METIS. */
#define metis_maxweight 10000.0f

/* Simple descriptions of initial partition types for reports. */
const char *initial_partition_name[] = {
    "gridded cells", "vectorized point associated cells",
    "METIS particle weighted cells", "METIS unweighted cells"};

/* Simple descriptions of repartition types for reports. */
const char *repartition_name[] = {
    "no",
    "METIS edge and vertex task cost weights",
    "METIS particle count vertex weights",