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mesh_partition_scotch.cc
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/**
* @file mesh_partition_scotch.cc
* @author Nicolas Richart <nicolas.richart@epfl.ch>
* @date Fri Aug 13 11:54:11 2010
*
* @brief implementation of the MeshPartitionScotch class
*
* @section LICENSE
*
* Copyright (©) 2010-2011 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
* Akantu 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.
*
* Akantu 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 Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Akantu. If not, see <http://www.gnu.org/licenses/>.
*
*/
/* -------------------------------------------------------------------------- */
#include <cstdio>
#include <fstream>
/* -------------------------------------------------------------------------- */
#include "mesh_partition_scotch.hh"
#include "mesh_utils.hh"
/* -------------------------------------------------------------------------- */
__BEGIN_AKANTU__
/* -------------------------------------------------------------------------- */
MeshPartitionScotch::MeshPartitionScotch(const Mesh & mesh, UInt spatial_dimension,
const MemoryID & memory_id) :
MeshPartition(mesh, spatial_dimension, memory_id) {
AKANTU_DEBUG_IN();
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
SCOTCH_Mesh * MeshPartitionScotch::createMesh() {
AKANTU_DEBUG_IN();
UInt spatial_dimension = mesh.getSpatialDimension();
UInt nb_nodes = mesh.getNbNodes();
UInt total_nb_element = 0;
UInt nb_edge = 0;
const Mesh::ConnectivityTypeList & type_list = mesh.getConnectivityTypeList();
Mesh::ConnectivityTypeList::const_iterator it;
for(it = type_list.begin(); it != type_list.end(); ++it) {
ElementType type = *it;
if(Mesh::getSpatialDimension(type) != spatial_dimension) continue;
UInt nb_element = mesh.getNbElement(type);
UInt nb_nodes_per_element = Mesh::getNbNodesPerElement(type);
total_nb_element += nb_element;
nb_edge += nb_element * nb_nodes_per_element;
}
SCOTCH_Num vnodbas = 0;
SCOTCH_Num vnodnbr = nb_nodes;
SCOTCH_Num velmbas = vnodnbr;
SCOTCH_Num velmnbr = total_nb_element;
SCOTCH_Num * verttab = new SCOTCH_Num[vnodnbr + velmnbr + 1];
SCOTCH_Num * vendtab = verttab + 1;
SCOTCH_Num * velotab = NULL;
SCOTCH_Num * vnlotab = NULL;
SCOTCH_Num * vlbltab = NULL;
memset(verttab, 0, (vnodnbr + velmnbr + 1) * sizeof(SCOTCH_Num));
for(it = type_list.begin(); it != type_list.end(); ++it) {
ElementType type = *it;
if(Mesh::getSpatialDimension(type) != spatial_dimension) continue;
UInt nb_element = mesh.getNbElement(type);
UInt nb_nodes_per_element = Mesh::getNbNodesPerElement(type);
const Vector<UInt> & connectivity = mesh.getConnectivity(type, _not_ghost);
/// count number of occurrence of each node
for (UInt el = 0; el < nb_element; ++el) {
UInt * conn_val = connectivity.values + el * nb_nodes_per_element;
for (UInt n = 0; n < nb_nodes_per_element; ++n) {
verttab[*(conn_val++)]++;
}
}
}
/// convert the occurrence array in a csr one
for (UInt i = 1; i < nb_nodes; ++i) verttab[i] += verttab[i-1];
for (UInt i = nb_nodes; i > 0; --i) verttab[i] = verttab[i-1];
verttab[0] = 0;
/// rearrange element to get the node-element list
SCOTCH_Num edgenbr = verttab[vnodnbr] + nb_edge;
SCOTCH_Num * edgetab = new SCOTCH_Num[edgenbr];
UInt linearized_el = 0;
for(it = type_list.begin(); it != type_list.end(); ++it) {
ElementType type = *it;
if(Mesh::getSpatialDimension(type) != spatial_dimension) continue;
UInt nb_element = mesh.getNbElement(type);
UInt nb_nodes_per_element = Mesh::getNbNodesPerElement(type);
const Vector<UInt> & connectivity = mesh.getConnectivity(type, _not_ghost);
for (UInt el = 0; el < nb_element; ++el, ++linearized_el) {
UInt * conn_val = connectivity.values + el * nb_nodes_per_element;
for (UInt n = 0; n < nb_nodes_per_element; ++n)
edgetab[verttab[*(conn_val++)]++] = linearized_el + velmbas;
}
}
for (UInt i = nb_nodes; i > 0; --i) verttab[i] = verttab[i-1];
verttab[0] = 0;
SCOTCH_Num * verttab_tmp = verttab + vnodnbr + 1;
SCOTCH_Num * edgetab_tmp = edgetab + verttab[vnodnbr];
for(it = type_list.begin(); it != type_list.end(); ++it) {
ElementType type = *it;
if(Mesh::getSpatialDimension(type) != mesh.getSpatialDimension()) continue;
UInt nb_element = mesh.getNbElement(type);
UInt nb_nodes_per_element = Mesh::getNbNodesPerElement(type);
const Vector<UInt> & connectivity = mesh.getConnectivity(type, _not_ghost);
for (UInt el = 0; el < nb_element; ++el) {
*verttab_tmp = *(verttab_tmp - 1) + nb_nodes_per_element;
verttab_tmp++;
UInt * conn = connectivity.values + el * nb_nodes_per_element;
for (UInt i = 0; i < nb_nodes_per_element; ++i) {
*(edgetab_tmp++) = *(conn++) + vnodbas;
}
}
}
SCOTCH_Mesh * meshptr = new SCOTCH_Mesh;
SCOTCH_meshInit(meshptr);
SCOTCH_meshBuild(meshptr,
velmbas, vnodbas,
velmnbr, vnodnbr,
verttab, vendtab,
velotab, vnlotab,
vlbltab,
edgenbr, edgetab);
/// Check the mesh
AKANTU_DEBUG_ASSERT(SCOTCH_meshCheck(meshptr) == 0,
"Scotch mesh is not consistent");
#ifndef AKANTU_NDEBUG
if (AKANTU_DEBUG_TEST(dblDump)) {
/// save initial graph
FILE *fmesh = fopen("ScotchMesh.msh", "w");
SCOTCH_meshSave(meshptr, fmesh);
fclose(fmesh);
/// write geometry file
std::ofstream fgeominit;
fgeominit.open("ScotchMesh.xyz");
fgeominit << spatial_dimension << std::endl << nb_nodes << std::endl;
const Vector<Real> & nodes = mesh.getNodes();
Real * nodes_val = nodes.values;
for (UInt i = 0; i < nb_nodes; ++i) {
fgeominit << i << " ";
for (UInt s = 0; s < spatial_dimension; ++s)
fgeominit << *(nodes_val++) << " ";
fgeominit << std::endl;;
}
fgeominit.close();
}
#endif
AKANTU_DEBUG_OUT();
return meshptr;
}
/* -------------------------------------------------------------------------- */
void MeshPartitionScotch::destroyMesh(SCOTCH_Mesh * meshptr) {
AKANTU_DEBUG_IN();
SCOTCH_Num velmbas, vnodbas,
vnodnbr, velmnbr,
*verttab, *vendtab,
*velotab, *vnlotab,
*vlbltab,
edgenbr, *edgetab,
degrptr;
SCOTCH_meshData(meshptr,
&velmbas, &vnodbas,
&velmnbr, &vnodnbr,
&verttab, &vendtab,
&velotab, &vnlotab,
&vlbltab,
&edgenbr, &edgetab,
&degrptr);
delete [] verttab;
delete [] edgetab;
SCOTCH_meshExit(meshptr);
delete meshptr;
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void MeshPartitionScotch::partitionate(UInt nb_part) {
AKANTU_DEBUG_IN();
nb_partitions = nb_part;
AKANTU_DEBUG_INFO("Partitioning the mesh " << mesh.getID()
<< " in " << nb_part << " parts.");
Vector<Int> dxadj;
Vector<Int> dadjncy;
buildDualGraph(dxadj, dadjncy);
/// variables that will hold our structures in scotch format
SCOTCH_Graph scotch_graph;
SCOTCH_Strat scotch_strat;
/// description number and arrays for struct mesh for scotch
SCOTCH_Num baseval = 0; //base numbering for element and
//nodes (0 -> C , 1 -> fortran)
SCOTCH_Num vertnbr = dxadj.getSize() - 1; //number of vertexes
SCOTCH_Num *parttab; //array of partitions
SCOTCH_Num edgenbr = dxadj.values[vertnbr]; //twice the number of "edges"
//(an "edge" bounds two nodes)
SCOTCH_Num * verttab = dxadj.values; //array of start indices in edgetab
SCOTCH_Num * vendtab = NULL; //array of after-last indices in edgetab
SCOTCH_Num * velotab = NULL; //integer load associated with
//every vertex ( optional )
SCOTCH_Num * edlotab = NULL; //integer load associated with
//every edge ( optional )
SCOTCH_Num * edgetab = dadjncy.values; // adjacency array of every vertex
SCOTCH_Num * vlbltab = NULL; // vertex label array (optional)
/// Allocate space for Scotch arrays
parttab = new SCOTCH_Num[vertnbr];
/// Initialize the strategy structure
SCOTCH_stratInit (&scotch_strat);
/// Initialize the graph structure
SCOTCH_graphInit(&scotch_graph);
/// Build the graph from the adjacency arrays
SCOTCH_graphBuild(&scotch_graph, baseval,
vertnbr, verttab, vendtab,
velotab, vlbltab, edgenbr,
edgetab, edlotab);
#ifndef AKANTU_NDEBUG
if (AKANTU_DEBUG_TEST(dblDump)) {
/// save initial graph
FILE *fgraphinit = fopen("GraphIniFile.grf", "w");
SCOTCH_graphSave(&scotch_graph,fgraphinit);
fclose(fgraphinit);
/// write geometry file
std::ofstream fgeominit;
fgeominit.open("GeomIniFile.xyz");
fgeominit << spatial_dimension << std::endl << vertnbr << std::endl;
const Vector<Real> & nodes = mesh.getNodes();
const Mesh::ConnectivityTypeList & f_type_list = mesh.getConnectivityTypeList();
Mesh::ConnectivityTypeList::const_iterator f_it;
UInt out_linerized_el = 0;
for(f_it = f_type_list.begin(); f_it != f_type_list.end(); ++f_it) {
ElementType type = *f_it;
if(Mesh::getSpatialDimension(type) != mesh.getSpatialDimension()) continue;
UInt nb_element = mesh.getNbElement(*f_it);
UInt nb_nodes_per_element = Mesh::getNbNodesPerElement(type);
const Vector<UInt> & connectivity = mesh.getConnectivity(type);
Real mid[spatial_dimension] ;
for (UInt el = 0; el < nb_element; ++el) {
memset(mid, 0, spatial_dimension*sizeof(Real));
for (UInt n = 0; n < nb_nodes_per_element; ++n) {
UInt node = connectivity.values[nb_nodes_per_element * el + n];
for (UInt s = 0; s < spatial_dimension; ++s)
mid[s] += ((Real) nodes.values[node * spatial_dimension + s]) / ((Real) nb_nodes_per_element);
}
fgeominit << out_linerized_el++ << " ";
for (UInt s = 0; s < spatial_dimension; ++s)
fgeominit << mid[s] << " ";
fgeominit << std::endl;;
}
}
fgeominit.close();
}
#endif
/// Check the graph
AKANTU_DEBUG_ASSERT(SCOTCH_graphCheck(&scotch_graph) == 0,
"Graph to partition is not consistent");
/// Partition the mesh
SCOTCH_graphPart(&scotch_graph, nb_part, &scotch_strat, parttab);
/// Check the graph
AKANTU_DEBUG_ASSERT(SCOTCH_graphCheck(&scotch_graph) == 0,
"Partitioned graph is not consistent");
#ifndef AKANTU_NDEBUG
if (AKANTU_DEBUG_TEST(dblDump)) {
/// save the partitioned graph
FILE *fgraph=fopen("GraphFile.grf", "w");
SCOTCH_graphSave(&scotch_graph, fgraph);
fclose(fgraph);
/// save the partition map
std::ofstream fmap;
fmap.open("MapFile.map");
fmap << vertnbr << std::endl;
for (Int i = 0; i < vertnbr; i++) fmap << i << " " << parttab[i] << std::endl;
fmap.close();
}
#endif
/// free the scotch data structures
SCOTCH_stratExit(&scotch_strat);
SCOTCH_graphFree(&scotch_graph);
SCOTCH_graphExit(&scotch_graph);
fillPartitionInformations(mesh, parttab);
delete [] parttab;
AKANTU_DEBUG_OUT();
}
/* -------------------------------------------------------------------------- */
void MeshPartitionScotch::reorder() {
AKANTU_DEBUG_IN();
AKANTU_DEBUG_INFO("Reordering the mesh " << mesh.getID());
SCOTCH_Mesh * scotch_mesh = createMesh();
UInt nb_nodes = mesh.getNbNodes();
SCOTCH_Strat scotch_strat;
// SCOTCH_Ordering scotch_order;
SCOTCH_Num * permtab = new SCOTCH_Num[nb_nodes];
SCOTCH_Num * peritab = NULL;
SCOTCH_Num cblknbr = 0;
SCOTCH_Num * rangtab = NULL;
SCOTCH_Num * treetab = NULL;
/// Initialize the strategy structure
SCOTCH_stratInit (&scotch_strat);
SCOTCH_Graph scotch_graph;
SCOTCH_graphInit(&scotch_graph);
SCOTCH_meshGraph(scotch_mesh, &scotch_graph);
#ifndef AKANTU_NDEBUG
if (AKANTU_DEBUG_TEST(dblDump)) {
FILE *fgraphinit = fopen("ScotchMesh.grf", "w");
SCOTCH_graphSave(&scotch_graph,fgraphinit);
fclose(fgraphinit);
}
#endif
/// Check the graph
// AKANTU_DEBUG_ASSERT(SCOTCH_graphCheck(&scotch_graph) == 0,
// "Mesh to Graph is not consistent");
SCOTCH_graphOrder(&scotch_graph, &scotch_strat,
permtab,
peritab,
&cblknbr,
rangtab,
treetab);
SCOTCH_graphExit(&scotch_graph);
SCOTCH_stratExit(&scotch_strat);
destroyMesh(scotch_mesh);
/// Renumbering
UInt spatial_dimension = mesh.getSpatialDimension();
for(UInt g = _not_ghost; g <= _ghost; ++g) {
GhostType gt = (GhostType) g;
const Mesh::ConnectivityTypeList & type_list = mesh.getConnectivityTypeList(gt);
Mesh::ConnectivityTypeList::const_iterator it;
for(it = type_list.begin(); it != type_list.end(); ++it) {
ElementType type = *it;
UInt nb_element = mesh.getNbElement(type, gt);
UInt nb_nodes_per_element = Mesh::getNbNodesPerElement(type);
const Vector<UInt> & connectivity = mesh.getConnectivity(type, gt);
UInt * conn = connectivity.values;
for (UInt el = 0; el < nb_element * nb_nodes_per_element; ++el, ++conn) {
*conn = permtab[*conn];
}
}
}
/// \todo think of a in-place way to do it
Real * new_coordinates = new Real[spatial_dimension * nb_nodes];
Real * old_coordinates = mesh.getNodes().values;
for (UInt i = 0; i < nb_nodes; ++i) {
memcpy(new_coordinates + permtab[i] * spatial_dimension,
old_coordinates + i * spatial_dimension,
spatial_dimension * sizeof(Real));
}
memcpy(old_coordinates, new_coordinates, nb_nodes * spatial_dimension * sizeof(Real));
delete [] new_coordinates;
delete [] permtab;
AKANTU_DEBUG_OUT();
}
__END_AKANTU__

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