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@google.com (Sameer Agarwal) 30 31#include "ceres/schur_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 42namespace ceres { 43namespace internal { 44 45int ComputeSchurOrdering(const Program& program, 46 vector<ParameterBlock*>* ordering) { 47 CHECK_NOTNULL(ordering)->clear(); 48 49 scoped_ptr<Graph< ParameterBlock*> > graph( 50 CHECK_NOTNULL(CreateHessianGraph(program))); 51 int independent_set_size = IndependentSetOrdering(*graph, ordering); 52 const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks(); 53 54 // Add the excluded blocks to back of the ordering vector. 55 for (int i = 0; i < parameter_blocks.size(); ++i) { 56 ParameterBlock* parameter_block = parameter_blocks[i]; 57 if (parameter_block->IsConstant()) { 58 ordering->push_back(parameter_block); 59 } 60 } 61 62 return independent_set_size; 63} 64 65Graph<ParameterBlock*>* 66CreateHessianGraph(const Program& program) { 67 Graph<ParameterBlock*>* graph = new Graph<ParameterBlock*>; 68 const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks(); 69 for (int i = 0; i < parameter_blocks.size(); ++i) { 70 ParameterBlock* parameter_block = parameter_blocks[i]; 71 if (!parameter_block->IsConstant()) { 72 graph->AddVertex(parameter_block); 73 } 74 } 75 76 const vector<ResidualBlock*>& residual_blocks = program.residual_blocks(); 77 for (int i = 0; i < residual_blocks.size(); ++i) { 78 const ResidualBlock* residual_block = residual_blocks[i]; 79 const int num_parameter_blocks = residual_block->NumParameterBlocks(); 80 ParameterBlock* const* parameter_blocks = 81 residual_block->parameter_blocks(); 82 for (int j = 0; j < num_parameter_blocks; ++j) { 83 if (parameter_blocks[j]->IsConstant()) { 84 continue; 85 } 86 87 for (int k = j + 1; k < num_parameter_blocks; ++k) { 88 if (parameter_blocks[k]->IsConstant()) { 89 continue; 90 } 91 92 graph->AddEdge(parameter_blocks[j], parameter_blocks[k]); 93 } 94 } 95 } 96 97 return graph; 98} 99 100} // namespace internal 101} // namespace ceres 102