Initial commit of Ceres Solver.
diff --git a/internal/ceres/graph.h b/internal/ceres/graph.h
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+// this list of conditions and the following disclaimer in the documentation
+// and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+// used to endorse or promote products derived from this software without
+// specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: sameeragarwal@google.com (Sameer Agarwal)
+
+#ifndef CERES_INTERNAL_GRAPH_H_
+#define CERES_INTERNAL_GRAPH_H_
+
+#include <limits>
+#include <glog/logging.h>
+#include "ceres/integral_types.h"
+#include "ceres/map_util.h"
+#include "ceres/collections_port.h"
+#include "ceres/internal/macros.h"
+#include "ceres/types.h"
+
+namespace ceres {
+namespace internal {
+
+// A weighted undirected graph templated over the vertex ids. Vertex
+// should be hashable and comparable.
+template <typename Vertex>
+class Graph {
+ public:
+ Graph() {}
+
+ // Add a weighted vertex. If the vertex already exists in the graph,
+ // its weight is set to the new weight.
+ void AddVertex(const Vertex& vertex, double weight) {
+ if (vertices_.find(vertex) == vertices_.end()) {
+ vertices_.insert(vertex);
+ edges_[vertex] = HashSet<Vertex>();
+ }
+ vertex_weights_[vertex] = weight;
+ }
+
+ // Uses weight = 1.0. If vertex already exists, its weight is set to
+ // 1.0.
+ void AddVertex(const Vertex& vertex) {
+ AddVertex(vertex, 1.0);
+ }
+
+ // Add a weighted edge between the vertex1 and vertex2. Calling
+ // AddEdge on a pair of vertices which do not exist in the graph yet
+ // will result in undefined behavior.
+ //
+ // It is legal to call this method repeatedly for the same set of
+ // vertices.
+ void AddEdge(const Vertex& vertex1, const Vertex& vertex2, double weight) {
+ DCHECK(vertices_.find(vertex1) != vertices_.end());
+ DCHECK(vertices_.find(vertex2) != vertices_.end());
+
+ if (edges_[vertex1].insert(vertex2).second) {
+ edges_[vertex2].insert(vertex1);
+ }
+
+ if (vertex1 < vertex2) {
+ edge_weights_[make_pair(vertex1, vertex2)] = weight;
+ } else {
+ edge_weights_[make_pair(vertex2, vertex1)] = weight;
+ }
+ }
+
+ // Uses weight = 1.0.
+ void AddEdge(const Vertex& vertex1, const Vertex& vertex2) {
+ AddEdge(vertex1, vertex2, 1.0);
+ }
+
+ // Calling VertexWeight on a vertex not in the graph will result in
+ // undefined behavior.
+ double VertexWeight(const Vertex& vertex) const {
+ return FindOrDie(vertex_weights_, vertex);
+ }
+
+ // Calling EdgeWeight on a pair of vertices where either one of the
+ // vertices is not present in the graph will result in undefined
+ // behaviour. If there is no edge connecting vertex1 and vertex2,
+ // the edge weight is zero.
+ double EdgeWeight(const Vertex& vertex1, const Vertex& vertex2) const {
+ if (vertex1 < vertex2) {
+ return FindWithDefault(edge_weights_, make_pair(vertex1, vertex2), 0.0);
+ } else {
+ return FindWithDefault(edge_weights_, make_pair(vertex2, vertex1), 0.0);
+ }
+ }
+
+ // Calling Neighbors on a vertex not in the graph will result in
+ // undefined behaviour.
+ const HashSet<Vertex>& Neighbors(const Vertex& vertex) const {
+ return FindOrDie(edges_, vertex);
+ }
+
+ const HashSet<Vertex>& vertices() const {
+ return vertices_;
+ }
+
+ static double InvalidWeight() {
+ return std::numeric_limits<double>::quiet_NaN();
+ };
+
+ private:
+ HashSet<Vertex> vertices_;
+ HashMap<Vertex, double> vertex_weights_;
+ HashMap<Vertex, HashSet<Vertex> > edges_;
+ HashMap<pair<Vertex, Vertex>, double> edge_weights_;
+
+ DISALLOW_COPY_AND_ASSIGN(Graph);
+};
+
+} // namespace internal
+} // namespace ceres
+
+#endif // CERES_INTERNAL_GRAPH_H_
