179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// Ceres Solver - A fast non-linear least squares minimizer 279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// Copyright 2013 Google Inc. All rights reserved. 379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// http://code.google.com/p/ceres-solver/ 479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// 579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// Redistribution and use in source and binary forms, with or without 679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// modification, are permitted provided that the following conditions are met: 779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// 879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// * Redistributions of source code must retain the above copyright notice, 979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// this list of conditions and the following disclaimer. 1079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// * Redistributions in binary form must reproduce the above copyright notice, 1179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// this list of conditions and the following disclaimer in the documentation 1279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// and/or other materials provided with the distribution. 1379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// * Neither the name of Google Inc. nor the names of its contributors may be 1479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// used to endorse or promote products derived from this software without 1579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// specific prior written permission. 1679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// 1779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 1879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 2179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 2279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 2379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 2479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 2579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 2679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 2779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// POSSIBILITY OF SUCH DAMAGE. 2879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// 2979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// Author: sameeragarwal@google.com (Sameer Agarwal) 3079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 3179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez// This include must come before any #ifndef check on Ceres compile options. 3279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#include "ceres/internal/port.h" 3379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 3479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#ifndef CERES_NO_SUITESPARSE 3579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 3679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#include "ceres/single_linkage_clustering.h" 3779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 3879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#include "ceres/graph.h" 3979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#include "ceres/collections_port.h" 4079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#include "ceres/graph_algorithms.h" 4179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 4279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandeznamespace ceres { 4379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandeznamespace internal { 4479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 4579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandezint ComputeSingleLinkageClustering( 4679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const SingleLinkageClusteringOptions& options, 4779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const Graph<int>& graph, 4879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez HashMap<int, int>* membership) { 4979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez CHECK_NOTNULL(membership)->clear(); 5079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 5179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez // Initially each vertex is in its own cluster. 5279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const HashSet<int>& vertices = graph.vertices(); 5379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez for (HashSet<int>::const_iterator it = vertices.begin(); 5479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez it != vertices.end(); 5579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez ++it) { 5679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez (*membership)[*it] = *it; 5779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 5879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 5979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez for (HashSet<int>::const_iterator it1 = vertices.begin(); 6079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez it1 != vertices.end(); 6179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez ++it1) { 6279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const int vertex1 = *it1; 6379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const HashSet<int>& neighbors = graph.Neighbors(vertex1); 6479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez for (HashSet<int>::const_iterator it2 = neighbors.begin(); 6579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez it2 != neighbors.end(); 6679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez ++it2) { 6779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const int vertex2 = *it2; 6879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 6979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez // Since the graph is undirected, only pay attention to one side 7079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez // of the edge and ignore weak edges. 7179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez if ((vertex1 > vertex2) || 7279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez (graph.EdgeWeight(vertex1, vertex2) < options.min_similarity)) { 7379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez continue; 7479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 7579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 7679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez // Use a union-find algorithm to keep track of the clusters. 7779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const int c1 = FindConnectedComponent(vertex1, membership); 7879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez const int c2 = FindConnectedComponent(vertex2, membership); 7979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 8079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez if (c1 == c2) { 8179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez continue; 8279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 8379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 8479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez if (c1 < c2) { 8579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez (*membership)[c2] = c1; 8679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } else { 8779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez (*membership)[c1] = c2; 8879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 8979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 9079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 9179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 9279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez // Make sure that every vertex is connected directly to the vertex 9379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez // identifying the cluster. 9479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez int num_clusters = 0; 9579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez for (HashMap<int, int>::iterator it = membership->begin(); 9679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez it != membership->end(); 9779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez ++it) { 9879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez it->second = FindConnectedComponent(it->first, membership); 9979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez if (it->first == it->second) { 10079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez ++num_clusters; 10179397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 10279397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez } 10379397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 10479397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez return num_clusters; 10579397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez} 10679397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 10779397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez} // namespace internal 10879397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez} // namespace ceres 10979397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez 11079397c21138f54fcff6ec067b44b847f1f7e0e98Carlos Hernandez#endif // CERES_NO_SUITESPARSE 111