|  | // Ceres Solver - A fast non-linear least squares minimizer | 
|  | // Copyright 2022 Google Inc. All rights reserved. | 
|  | // http://ceres-solver.org/ | 
|  | // | 
|  | // 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: keir@google.com (Keir Mierle) | 
|  |  | 
|  | #include "ceres/compressed_row_jacobian_writer.h" | 
|  |  | 
|  | #include <algorithm> | 
|  | #include <iterator> | 
|  | #include <memory> | 
|  | #include <string> | 
|  | #include <utility> | 
|  | #include <vector> | 
|  |  | 
|  | #include "ceres/casts.h" | 
|  | #include "ceres/compressed_row_sparse_matrix.h" | 
|  | #include "ceres/parameter_block.h" | 
|  | #include "ceres/program.h" | 
|  | #include "ceres/residual_block.h" | 
|  | #include "ceres/scratch_evaluate_preparer.h" | 
|  |  | 
|  | namespace ceres::internal { | 
|  | void CompressedRowJacobianWriter::PopulateJacobianRowAndColumnBlockVectors( | 
|  | const Program* program, CompressedRowSparseMatrix* jacobian) { | 
|  | const auto& parameter_blocks = program->parameter_blocks(); | 
|  | auto& col_blocks = *(jacobian->mutable_col_blocks()); | 
|  | col_blocks.resize(parameter_blocks.size()); | 
|  | int col_pos = 0; | 
|  | for (int i = 0; i < parameter_blocks.size(); ++i) { | 
|  | col_blocks[i].size = parameter_blocks[i]->TangentSize(); | 
|  | col_blocks[i].position = col_pos; | 
|  | col_pos += col_blocks[i].size; | 
|  | } | 
|  |  | 
|  | const auto& residual_blocks = program->residual_blocks(); | 
|  | auto& row_blocks = *(jacobian->mutable_row_blocks()); | 
|  | row_blocks.resize(residual_blocks.size()); | 
|  | int row_pos = 0; | 
|  | for (int i = 0; i < residual_blocks.size(); ++i) { | 
|  | row_blocks[i].size = residual_blocks[i]->NumResiduals(); | 
|  | row_blocks[i].position = row_pos; | 
|  | row_pos += row_blocks[i].size; | 
|  | } | 
|  | } | 
|  |  | 
|  | void CompressedRowJacobianWriter::GetOrderedParameterBlocks( | 
|  | const Program* program, | 
|  | int residual_id, | 
|  | std::vector<std::pair<int, int>>* evaluated_jacobian_blocks) { | 
|  | auto residual_block = program->residual_blocks()[residual_id]; | 
|  | const int num_parameter_blocks = residual_block->NumParameterBlocks(); | 
|  |  | 
|  | for (int j = 0; j < num_parameter_blocks; ++j) { | 
|  | auto parameter_block = residual_block->parameter_blocks()[j]; | 
|  | if (!parameter_block->IsConstant()) { | 
|  | evaluated_jacobian_blocks->push_back( | 
|  | std::make_pair(parameter_block->index(), j)); | 
|  | } | 
|  | } | 
|  | std::sort(evaluated_jacobian_blocks->begin(), | 
|  | evaluated_jacobian_blocks->end()); | 
|  | } | 
|  |  | 
|  | std::unique_ptr<SparseMatrix> CompressedRowJacobianWriter::CreateJacobian() | 
|  | const { | 
|  | const auto& residual_blocks = program_->residual_blocks(); | 
|  |  | 
|  | int total_num_residuals = program_->NumResiduals(); | 
|  | int total_num_effective_parameters = program_->NumEffectiveParameters(); | 
|  |  | 
|  | // Count the number of jacobian nonzeros. | 
|  | int num_jacobian_nonzeros = 0; | 
|  | for (auto* residual_block : residual_blocks) { | 
|  | const int num_residuals = residual_block->NumResiduals(); | 
|  | const int num_parameter_blocks = residual_block->NumParameterBlocks(); | 
|  | for (int j = 0; j < num_parameter_blocks; ++j) { | 
|  | auto parameter_block = residual_block->parameter_blocks()[j]; | 
|  | if (!parameter_block->IsConstant()) { | 
|  | num_jacobian_nonzeros += num_residuals * parameter_block->TangentSize(); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // Allocate storage for the jacobian with some extra space at the end. | 
|  | // Allocate more space than needed to store the jacobian so that when the LM | 
|  | // algorithm adds the diagonal, no reallocation is necessary. This reduces | 
|  | // peak memory usage significantly. | 
|  | auto jacobian = std::make_unique<CompressedRowSparseMatrix>( | 
|  | total_num_residuals, | 
|  | total_num_effective_parameters, | 
|  | num_jacobian_nonzeros + total_num_effective_parameters); | 
|  |  | 
|  | // At this stage, the CompressedRowSparseMatrix is an invalid state. But | 
|  | // this seems to be the only way to construct it without doing a memory | 
|  | // copy. | 
|  | int* rows = jacobian->mutable_rows(); | 
|  | int* cols = jacobian->mutable_cols(); | 
|  |  | 
|  | int row_pos = 0; | 
|  | rows[0] = 0; | 
|  | for (auto* residual_block : residual_blocks) { | 
|  | const int num_parameter_blocks = residual_block->NumParameterBlocks(); | 
|  |  | 
|  | // Count the number of derivatives for a row of this residual block and | 
|  | // build a list of active parameter block indices. | 
|  | int num_derivatives = 0; | 
|  | std::vector<int> parameter_indices; | 
|  | for (int j = 0; j < num_parameter_blocks; ++j) { | 
|  | auto parameter_block = residual_block->parameter_blocks()[j]; | 
|  | if (!parameter_block->IsConstant()) { | 
|  | parameter_indices.push_back(parameter_block->index()); | 
|  | num_derivatives += parameter_block->TangentSize(); | 
|  | } | 
|  | } | 
|  |  | 
|  | // Sort the parameters by their position in the state vector. | 
|  | std::sort(parameter_indices.begin(), parameter_indices.end()); | 
|  | if (adjacent_find(parameter_indices.begin(), parameter_indices.end()) != | 
|  | parameter_indices.end()) { | 
|  | std::string parameter_block_description; | 
|  | for (int j = 0; j < num_parameter_blocks; ++j) { | 
|  | auto parameter_block = residual_block->parameter_blocks()[j]; | 
|  | parameter_block_description += parameter_block->ToString() + "\n"; | 
|  | } | 
|  | LOG(FATAL) << "Ceres internal error: " | 
|  | << "Duplicate parameter blocks detected in a cost function. " | 
|  | << "This should never happen. Please report this to " | 
|  | << "the Ceres developers.\n" | 
|  | << "Residual Block: " << residual_block->ToString() << "\n" | 
|  | << "Parameter Blocks: " << parameter_block_description; | 
|  | } | 
|  |  | 
|  | // Update the row indices. | 
|  | const int num_residuals = residual_block->NumResiduals(); | 
|  | for (int j = 0; j < num_residuals; ++j) { | 
|  | rows[row_pos + j + 1] = rows[row_pos + j] + num_derivatives; | 
|  | } | 
|  |  | 
|  | // Iterate over parameter blocks in the order which they occur in the | 
|  | // parameter vector. This code mirrors that in Write(), where jacobian | 
|  | // values are updated. | 
|  | int col_pos = 0; | 
|  | for (int parameter_index : parameter_indices) { | 
|  | auto parameter_block = program_->parameter_blocks()[parameter_index]; | 
|  | const int parameter_block_size = parameter_block->TangentSize(); | 
|  |  | 
|  | for (int r = 0; r < num_residuals; ++r) { | 
|  | // This is the position in the values array of the jacobian where this | 
|  | // row of the jacobian block should go. | 
|  | const int column_block_begin = rows[row_pos + r] + col_pos; | 
|  | for (int c = 0; c < parameter_block_size; ++c) { | 
|  | cols[column_block_begin + c] = parameter_block->delta_offset() + c; | 
|  | } | 
|  | } | 
|  | col_pos += parameter_block_size; | 
|  | } | 
|  | row_pos += num_residuals; | 
|  | } | 
|  | CHECK_EQ(num_jacobian_nonzeros, rows[total_num_residuals]); | 
|  |  | 
|  | PopulateJacobianRowAndColumnBlockVectors(program_, jacobian.get()); | 
|  |  | 
|  | return jacobian; | 
|  | } | 
|  |  | 
|  | void CompressedRowJacobianWriter::Write(int residual_id, | 
|  | int residual_offset, | 
|  | double** jacobians, | 
|  | SparseMatrix* base_jacobian) { | 
|  | auto* jacobian = down_cast<CompressedRowSparseMatrix*>(base_jacobian); | 
|  |  | 
|  | double* jacobian_values = jacobian->mutable_values(); | 
|  | const int* jacobian_rows = jacobian->rows(); | 
|  |  | 
|  | auto residual_block = program_->residual_blocks()[residual_id]; | 
|  | const int num_residuals = residual_block->NumResiduals(); | 
|  |  | 
|  | std::vector<std::pair<int, int>> evaluated_jacobian_blocks; | 
|  | GetOrderedParameterBlocks(program_, residual_id, &evaluated_jacobian_blocks); | 
|  |  | 
|  | // Where in the current row does the jacobian for a parameter block begin. | 
|  | int col_pos = 0; | 
|  |  | 
|  | // Iterate over the jacobian blocks in increasing order of their | 
|  | // positions in the reduced parameter vector. | 
|  | for (auto& evaluated_jacobian_block : evaluated_jacobian_blocks) { | 
|  | auto parameter_block = | 
|  | program_->parameter_blocks()[evaluated_jacobian_block.first]; | 
|  | const int argument = evaluated_jacobian_block.second; | 
|  | const int parameter_block_size = parameter_block->TangentSize(); | 
|  |  | 
|  | // Copy one row of the jacobian block at a time. | 
|  | for (int r = 0; r < num_residuals; ++r) { | 
|  | // Position of the r^th row of the current jacobian block. | 
|  | const double* block_row_begin = | 
|  | jacobians[argument] + r * parameter_block_size; | 
|  |  | 
|  | // Position in the values array of the jacobian where this | 
|  | // row of the jacobian block should go. | 
|  | double* column_block_begin = | 
|  | jacobian_values + jacobian_rows[residual_offset + r] + col_pos; | 
|  |  | 
|  | std::copy(block_row_begin, | 
|  | block_row_begin + parameter_block_size, | 
|  | column_block_begin); | 
|  | } | 
|  | col_pos += parameter_block_size; | 
|  | } | 
|  | } | 
|  |  | 
|  | }  // namespace ceres::internal |