Squashed 'third_party/ceres/' content from commit e51e9b4
Change-Id: I763587619d57e594d3fa158dc3a7fe0b89a1743b
git-subtree-dir: third_party/ceres
git-subtree-split: e51e9b46f6ca88ab8b2266d0e362771db6d98067
diff --git a/internal/ceres/parameter_block_ordering.cc b/internal/ceres/parameter_block_ordering.cc
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2015 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: sameeragarwal@google.com (Sameer Agarwal)
+
+#include "ceres/parameter_block_ordering.h"
+
+#include <memory>
+#include <unordered_set>
+
+#include "ceres/graph.h"
+#include "ceres/graph_algorithms.h"
+#include "ceres/map_util.h"
+#include "ceres/parameter_block.h"
+#include "ceres/program.h"
+#include "ceres/residual_block.h"
+#include "ceres/wall_time.h"
+#include "glog/logging.h"
+
+namespace ceres {
+namespace internal {
+
+using std::map;
+using std::set;
+using std::vector;
+
+int ComputeStableSchurOrdering(const Program& program,
+ vector<ParameterBlock*>* ordering) {
+ CHECK(ordering != nullptr);
+ ordering->clear();
+ EventLogger event_logger("ComputeStableSchurOrdering");
+ std::unique_ptr<Graph< ParameterBlock*> > graph(CreateHessianGraph(program));
+ event_logger.AddEvent("CreateHessianGraph");
+
+ const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks();
+ const std::unordered_set<ParameterBlock*>& vertices = graph->vertices();
+ for (int i = 0; i < parameter_blocks.size(); ++i) {
+ if (vertices.count(parameter_blocks[i]) > 0) {
+ ordering->push_back(parameter_blocks[i]);
+ }
+ }
+ event_logger.AddEvent("Preordering");
+
+ int independent_set_size = StableIndependentSetOrdering(*graph, ordering);
+ event_logger.AddEvent("StableIndependentSet");
+
+ // Add the excluded blocks to back of the ordering vector.
+ for (int i = 0; i < parameter_blocks.size(); ++i) {
+ ParameterBlock* parameter_block = parameter_blocks[i];
+ if (parameter_block->IsConstant()) {
+ ordering->push_back(parameter_block);
+ }
+ }
+ event_logger.AddEvent("ConstantParameterBlocks");
+
+ return independent_set_size;
+}
+
+int ComputeSchurOrdering(const Program& program,
+ vector<ParameterBlock*>* ordering) {
+ CHECK(ordering != nullptr);
+ ordering->clear();
+
+ std::unique_ptr<Graph< ParameterBlock*> > graph(CreateHessianGraph(program));
+ int independent_set_size = IndependentSetOrdering(*graph, ordering);
+ const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks();
+
+ // Add the excluded blocks to back of the ordering vector.
+ for (int i = 0; i < parameter_blocks.size(); ++i) {
+ ParameterBlock* parameter_block = parameter_blocks[i];
+ if (parameter_block->IsConstant()) {
+ ordering->push_back(parameter_block);
+ }
+ }
+
+ return independent_set_size;
+}
+
+void ComputeRecursiveIndependentSetOrdering(const Program& program,
+ ParameterBlockOrdering* ordering) {
+ CHECK(ordering != nullptr);
+ ordering->Clear();
+ const vector<ParameterBlock*> parameter_blocks = program.parameter_blocks();
+ std::unique_ptr<Graph< ParameterBlock*> > graph(CreateHessianGraph(program));
+
+ int num_covered = 0;
+ int round = 0;
+ while (num_covered < parameter_blocks.size()) {
+ vector<ParameterBlock*> independent_set_ordering;
+ const int independent_set_size =
+ IndependentSetOrdering(*graph, &independent_set_ordering);
+ for (int i = 0; i < independent_set_size; ++i) {
+ ParameterBlock* parameter_block = independent_set_ordering[i];
+ ordering->AddElementToGroup(parameter_block->mutable_user_state(), round);
+ graph->RemoveVertex(parameter_block);
+ }
+ num_covered += independent_set_size;
+ ++round;
+ }
+}
+
+Graph<ParameterBlock*>* CreateHessianGraph(const Program& program) {
+ Graph<ParameterBlock*>* graph = new Graph<ParameterBlock*>;
+ CHECK(graph != nullptr);
+ const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks();
+ for (int i = 0; i < parameter_blocks.size(); ++i) {
+ ParameterBlock* parameter_block = parameter_blocks[i];
+ if (!parameter_block->IsConstant()) {
+ graph->AddVertex(parameter_block);
+ }
+ }
+
+ const vector<ResidualBlock*>& residual_blocks = program.residual_blocks();
+ for (int i = 0; i < residual_blocks.size(); ++i) {
+ const ResidualBlock* residual_block = residual_blocks[i];
+ const int num_parameter_blocks = residual_block->NumParameterBlocks();
+ ParameterBlock* const* parameter_blocks =
+ residual_block->parameter_blocks();
+ for (int j = 0; j < num_parameter_blocks; ++j) {
+ if (parameter_blocks[j]->IsConstant()) {
+ continue;
+ }
+
+ for (int k = j + 1; k < num_parameter_blocks; ++k) {
+ if (parameter_blocks[k]->IsConstant()) {
+ continue;
+ }
+
+ graph->AddEdge(parameter_blocks[j], parameter_blocks[k]);
+ }
+ }
+ }
+
+ return graph;
+}
+
+void OrderingToGroupSizes(const ParameterBlockOrdering* ordering,
+ vector<int>* group_sizes) {
+ CHECK(group_sizes != nullptr);
+ group_sizes->clear();
+ if (ordering == NULL) {
+ return;
+ }
+
+ const map<int, set<double*>>& group_to_elements =
+ ordering->group_to_elements();
+ for (const auto& g_t_e : group_to_elements) {
+ group_sizes->push_back(g_t_e.second.size());
+ }
+}
+
+} // namespace internal
+} // namespace ceres