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BoostGraphColoring.h
// Copyright (C) 2010 Garth N. Wells
//
// This file is part of DOLFIN.
//
// DOLFIN 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.
//
// DOLFIN 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 DOLFIN. If not, see <http://www.gnu.org/licenses/>.
//
// First added: 2010-11-24
// Last changed:
#ifndef __DOLFIN_BOOST_GRAPH_INTERFACE_H
#define __DOLFIN_BOOST_GRAPH_INTERFACE_H
#include <iostream>
#include <vector>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/compressed_sparse_row_graph.hpp>
#include <boost/graph/sequential_vertex_coloring.hpp>
#include <dolfin/common/Timer.h>
#include "Graph.h"
namespace dolfin
{
class Mesh;
class BoostGraphColoring
{
public:
template<typename ColorType>
static std::size_t compute_local_vertex_coloring(const Graph& graph,
std::vector<ColorType>& colors)
{
Timer timer("Boost graph coloring (from dolfin::Graph)");
// Typedef for Boost compressed sparse row graph
typedef boost::compressed_sparse_row_graph<boost::directedS,
boost::property<boost::vertex_color_t, ColorType> > BoostGraph;
// Number of vertices
const std::size_t n = graph.size();
// Count number of edges
Graph::const_iterator vertex;
std::size_t num_edges = 0;
for (vertex = graph.begin(); vertex != graph.end(); ++vertex)
num_edges += vertex->size();
// Build list of graph edges
std::vector<std::pair<std::size_t, std::size_t> > edges;
edges.reserve(num_edges);
graph_set_type::const_iterator edge;
for (vertex = graph.begin(); vertex != graph.end(); ++vertex)
{
for (edge = vertex->begin(); edge != vertex->end(); ++edge)
{
const std::size_t vertex_index = vertex - graph.begin();
if (vertex_index != (std::size_t) *edge)
edges.push_back(std::make_pair(vertex_index, *edge));
}
}
// Build Boost graph
const BoostGraph g(boost::edges_are_unsorted_multi_pass,
edges.begin(), edges.end(), n);
// Resize vector to hold colors
colors.resize(n);
// Perform coloring
return compute_local_vertex_coloring(g, colors);
}
template<typename T, typename ColorType>
static std::size_t compute_local_vertex_coloring(const T& graph,
std::vector<ColorType>& colors)
{
Timer timer("Boost graph coloring");
// Number of vertices in graph
const std::size_t num_vertices = boost::num_vertices(graph);
dolfin_assert(num_vertices == colors.size());
typedef typename boost::graph_traits<T>::vertices_size_type
vert_size_type;
typedef typename boost::property_map<T,
boost::vertex_index_t>::const_type vert_index_map;
// Resize to hold colors
colors.resize(num_vertices);
// Color vertices
std::vector<vert_size_type> _colors(num_vertices);
boost::iterator_property_map<vert_size_type*, vert_index_map>
color(&_colors.front(), get(boost::vertex_index, graph));
const vert_size_type num_colors = sequential_vertex_coloring(graph,
color);
// Copy colors and return
std::copy(_colors.begin(), _colors.end(), colors.begin());
return num_colors;
}
};
}
#endif
dolfin::BoostGraphColoring
This class colors a graph using the Boost Graph Library.
Definition BoostGraphColoring.h:41
dolfin::BoostGraphColoring::compute_local_vertex_coloring
static std::size_t compute_local_vertex_coloring(const Graph &graph, std::vector< ColorType > &colors)
Compute vertex colors.
Definition BoostGraphColoring.h:47
dolfin::BoostGraphColoring::compute_local_vertex_coloring
static std::size_t compute_local_vertex_coloring(const T &graph, std::vector< ColorType > &colors)
Compute vertex colors.
Definition BoostGraphColoring.h:91
dolfin::Mesh
Definition Mesh.h:84
dolfin::Set< int >::const_iterator
std::vector< int >::const_iterator const_iterator
Definition Set.h:43
dolfin::Timer
Definition Timer.h:48
dolfin
Definition adapt.h:30
dolfin::Graph
std::vector< graph_set_type > Graph
Vector of unordered Sets.
Definition Graph.h:39