1 // Ceres Solver - A fast non-linear least squares minimizer 2 // Copyright 2010, 2011, 2012 Google Inc. All rights reserved. 3 // http://code.google.com/p/ceres-solver/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are met: 7 // 8 // * Redistributions of source code must retain the above copyright notice, 9 // this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright notice, 11 // this list of conditions and the following disclaimer in the documentation 12 // and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors may be 14 // used to endorse or promote products derived from this software without 15 // specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 // POSSIBILITY OF SUCH DAMAGE. 28 // 29 // Author: sameeragarwal (at) google.com (Sameer Agarwal) 30 31 #include "ceres/parameter_block_ordering.h" 32 33 #include "ceres/graph.h" 34 #include "ceres/graph_algorithms.h" 35 #include "ceres/internal/scoped_ptr.h" 36 #include "ceres/map_util.h" 37 #include "ceres/parameter_block.h" 38 #include "ceres/program.h" 39 #include "ceres/residual_block.h" 40 #include "glog/logging.h" 41 42 namespace ceres { 43 namespace internal { 44 45 int ComputeSchurOrdering(const Program& program, 46 vector<ParameterBlock*>* ordering) { 47 CHECK_NOTNULL(ordering)->clear(); 48 49 scoped_ptr<Graph< ParameterBlock*> > graph(CreateHessianGraph(program)); 50 int independent_set_size = IndependentSetOrdering(*graph, ordering); 51 const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks(); 52 53 // Add the excluded blocks to back of the ordering vector. 54 for (int i = 0; i < parameter_blocks.size(); ++i) { 55 ParameterBlock* parameter_block = parameter_blocks[i]; 56 if (parameter_block->IsConstant()) { 57 ordering->push_back(parameter_block); 58 } 59 } 60 61 return independent_set_size; 62 } 63 64 void ComputeRecursiveIndependentSetOrdering(const Program& program, 65 ParameterBlockOrdering* ordering) { 66 CHECK_NOTNULL(ordering)->Clear(); 67 const vector<ParameterBlock*> parameter_blocks = program.parameter_blocks(); 68 scoped_ptr<Graph< ParameterBlock*> > graph(CreateHessianGraph(program)); 69 70 int num_covered = 0; 71 int round = 0; 72 while (num_covered < parameter_blocks.size()) { 73 vector<ParameterBlock*> independent_set_ordering; 74 const int independent_set_size = 75 IndependentSetOrdering(*graph, &independent_set_ordering); 76 for (int i = 0; i < independent_set_size; ++i) { 77 ParameterBlock* parameter_block = independent_set_ordering[i]; 78 ordering->AddElementToGroup(parameter_block->mutable_user_state(), round); 79 graph->RemoveVertex(parameter_block); 80 } 81 num_covered += independent_set_size; 82 ++round; 83 } 84 } 85 86 Graph<ParameterBlock*>* 87 CreateHessianGraph(const Program& program) { 88 Graph<ParameterBlock*>* graph = CHECK_NOTNULL(new Graph<ParameterBlock*>); 89 const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks(); 90 for (int i = 0; i < parameter_blocks.size(); ++i) { 91 ParameterBlock* parameter_block = parameter_blocks[i]; 92 if (!parameter_block->IsConstant()) { 93 graph->AddVertex(parameter_block); 94 } 95 } 96 97 const vector<ResidualBlock*>& residual_blocks = program.residual_blocks(); 98 for (int i = 0; i < residual_blocks.size(); ++i) { 99 const ResidualBlock* residual_block = residual_blocks[i]; 100 const int num_parameter_blocks = residual_block->NumParameterBlocks(); 101 ParameterBlock* const* parameter_blocks = 102 residual_block->parameter_blocks(); 103 for (int j = 0; j < num_parameter_blocks; ++j) { 104 if (parameter_blocks[j]->IsConstant()) { 105 continue; 106 } 107 108 for (int k = j + 1; k < num_parameter_blocks; ++k) { 109 if (parameter_blocks[k]->IsConstant()) { 110 continue; 111 } 112 113 graph->AddEdge(parameter_blocks[j], parameter_blocks[k]); 114 } 115 } 116 } 117 118 return graph; 119 } 120 121 } // namespace internal 122 } // namespace ceres 123