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: keir (at) google.com (Keir Mierle) 30 31 #include "ceres/compressed_row_jacobian_writer.h" 32 33 #include "ceres/casts.h" 34 #include "ceres/compressed_row_sparse_matrix.h" 35 #include "ceres/parameter_block.h" 36 #include "ceres/program.h" 37 #include "ceres/residual_block.h" 38 #include "ceres/scratch_evaluate_preparer.h" 39 40 namespace ceres { 41 namespace internal { 42 43 SparseMatrix* CompressedRowJacobianWriter::CreateJacobian() const { 44 const vector<ResidualBlock*>& residual_blocks = 45 program_->residual_blocks(); 46 47 int total_num_residuals = program_->NumResiduals(); 48 int total_num_effective_parameters = program_->NumEffectiveParameters(); 49 50 // Count the number of jacobian nonzeros. 51 int num_jacobian_nonzeros = 0; 52 for (int i = 0; i < residual_blocks.size(); ++i) { 53 ResidualBlock* residual_block = residual_blocks[i]; 54 const int num_residuals = residual_block->NumResiduals(); 55 const int num_parameter_blocks = residual_block->NumParameterBlocks(); 56 for (int j = 0; j < num_parameter_blocks; ++j) { 57 ParameterBlock* parameter_block = residual_block->parameter_blocks()[j]; 58 if (!parameter_block->IsConstant()) { 59 num_jacobian_nonzeros += num_residuals * parameter_block->LocalSize(); 60 } 61 } 62 } 63 64 // Allocate storage for the jacobian with some extra space at the end. 65 // Allocate more space than needed to store the jacobian so that when the LM 66 // algorithm adds the diagonal, no reallocation is necessary. This reduces 67 // peak memory usage significantly. 68 CompressedRowSparseMatrix* jacobian = 69 new CompressedRowSparseMatrix( 70 total_num_residuals, 71 total_num_effective_parameters, 72 num_jacobian_nonzeros + total_num_effective_parameters); 73 74 // At this stage, the CompressedSparseMatrix is an invalid state. But this 75 // seems to be the only way to construct it without doing a memory copy. 76 int* rows = jacobian->mutable_rows(); 77 int* cols = jacobian->mutable_cols(); 78 int row_pos = 0; 79 rows[0] = 0; 80 for (int i = 0; i < residual_blocks.size(); ++i) { 81 const ResidualBlock* residual_block = residual_blocks[i]; 82 const int num_parameter_blocks = residual_block->NumParameterBlocks(); 83 84 // Count the number of derivatives for a row of this residual block and 85 // build a list of active parameter block indices. 86 int num_derivatives = 0; 87 vector<int> parameter_indices; 88 for (int j = 0; j < num_parameter_blocks; ++j) { 89 ParameterBlock* parameter_block = residual_block->parameter_blocks()[j]; 90 if (!parameter_block->IsConstant()) { 91 parameter_indices.push_back(parameter_block->index()); 92 num_derivatives += parameter_block->LocalSize(); 93 } 94 } 95 96 // Sort the parameters by their position in the state vector. 97 sort(parameter_indices.begin(), parameter_indices.end()); 98 CHECK(unique(parameter_indices.begin(), parameter_indices.end()) == 99 parameter_indices.end()) 100 << "Ceres internal error: " 101 << "Duplicate parameter blocks detected in a cost function. " 102 << "This should never happen. Please report this to " 103 << "the Ceres developers."; 104 105 // Update the row indices. 106 const int num_residuals = residual_block->NumResiduals(); 107 for (int j = 0; j < num_residuals; ++j) { 108 rows[row_pos + j + 1] = rows[row_pos + j] + num_derivatives; 109 } 110 111 // Iterate over parameter blocks in the order which they occur in the 112 // parameter vector. This code mirrors that in Write(), where jacobian 113 // values are updated. 114 int col_pos = 0; 115 for (int j = 0; j < parameter_indices.size(); ++j) { 116 ParameterBlock* parameter_block = 117 program_->parameter_blocks()[parameter_indices[j]]; 118 const int parameter_block_size = parameter_block->LocalSize(); 119 120 for (int r = 0; r < num_residuals; ++r) { 121 // This is the position in the values array of the jacobian where this 122 // row of the jacobian block should go. 123 const int column_block_begin = rows[row_pos + r] + col_pos; 124 125 for (int c = 0; c < parameter_block_size; ++c) { 126 cols[column_block_begin + c] = parameter_block->delta_offset() + c; 127 } 128 } 129 col_pos += parameter_block_size; 130 } 131 row_pos += num_residuals; 132 } 133 CHECK_EQ(num_jacobian_nonzeros, rows[total_num_residuals]); 134 135 // Populate the row and column block vectors for use by block 136 // oriented ordering algorithms. This is useful when 137 // Solver::Options::use_block_amd = true. 138 const vector<ParameterBlock*>& parameter_blocks = 139 program_->parameter_blocks(); 140 vector<int>& col_blocks = *(jacobian->mutable_col_blocks()); 141 col_blocks.resize(parameter_blocks.size()); 142 for (int i = 0; i < parameter_blocks.size(); ++i) { 143 col_blocks[i] = parameter_blocks[i]->LocalSize(); 144 } 145 146 vector<int>& row_blocks = *(jacobian->mutable_row_blocks()); 147 row_blocks.resize(residual_blocks.size()); 148 for (int i = 0; i < residual_blocks.size(); ++i) { 149 row_blocks[i] = residual_blocks[i]->NumResiduals(); 150 } 151 152 return jacobian; 153 } 154 155 void CompressedRowJacobianWriter::Write(int residual_id, 156 int residual_offset, 157 double **jacobians, 158 SparseMatrix* base_jacobian) { 159 CompressedRowSparseMatrix* jacobian = 160 down_cast<CompressedRowSparseMatrix*>(base_jacobian); 161 162 double* jacobian_values = jacobian->mutable_values(); 163 const int* jacobian_rows = jacobian->rows(); 164 165 const ResidualBlock* residual_block = 166 program_->residual_blocks()[residual_id]; 167 const int num_parameter_blocks = residual_block->NumParameterBlocks(); 168 const int num_residuals = residual_block->NumResiduals(); 169 170 // It is necessary to determine the order of the jacobian blocks before 171 // copying them into the CompressedRowSparseMatrix. Just because a cost 172 // function uses parameter blocks 1 after 2 in its arguments does not mean 173 // that the block 1 occurs before block 2 in the column layout of the 174 // jacobian. Thus, determine the order by sorting the jacobian blocks by their 175 // position in the state vector. 176 vector<pair<int, int> > evaluated_jacobian_blocks; 177 for (int j = 0; j < num_parameter_blocks; ++j) { 178 const ParameterBlock* parameter_block = 179 residual_block->parameter_blocks()[j]; 180 if (!parameter_block->IsConstant()) { 181 evaluated_jacobian_blocks.push_back( 182 make_pair(parameter_block->index(), j)); 183 } 184 } 185 sort(evaluated_jacobian_blocks.begin(), evaluated_jacobian_blocks.end()); 186 187 // Where in the current row does the jacobian for a parameter block begin. 188 int col_pos = 0; 189 190 // Iterate over the jacobian blocks in increasing order of their 191 // positions in the reduced parameter vector. 192 for (int i = 0; i < evaluated_jacobian_blocks.size(); ++i) { 193 const ParameterBlock* parameter_block = 194 program_->parameter_blocks()[evaluated_jacobian_blocks[i].first]; 195 const int argument = evaluated_jacobian_blocks[i].second; 196 const int parameter_block_size = parameter_block->LocalSize(); 197 198 // Copy one row of the jacobian block at a time. 199 for (int r = 0; r < num_residuals; ++r) { 200 // Position of the r^th row of the current jacobian block. 201 const double* block_row_begin = 202 jacobians[argument] + r * parameter_block_size; 203 204 // Position in the values array of the jacobian where this 205 // row of the jacobian block should go. 206 double* column_block_begin = 207 jacobian_values + jacobian_rows[residual_offset + r] + col_pos; 208 209 copy(block_row_begin, 210 block_row_begin + parameter_block_size, 211 column_block_begin); 212 } 213 col_pos += parameter_block_size; 214 } 215 } 216 217 } // namespace internal 218 } // namespace ceres 219