261 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			261 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
/* ----------------------------------------------------------------------------
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 * GTSAM Copyright 2010, Georgia Tech Research Corporation,
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 * Atlanta, Georgia 30332-0415
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 * All Rights Reserved
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 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
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 * See LICENSE for the license information
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 * -------------------------------------------------------------------------- */
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/**
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 * @file    ConcurrentIncrementalSmoother.cpp
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 * @brief   An iSAM2-based Smoother that implements the
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 *          Concurrent Filtering and Smoothing interface.
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 * @author  Stephen Williams
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 */
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#include <gtsam_unstable/nonlinear/ConcurrentIncrementalSmoother.h>
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#include <gtsam/nonlinear/LinearContainerFactor.h>
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#include <gtsam/base/timing.h>
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#include <gtsam/base/debug.h>
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namespace gtsam {
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/* ************************************************************************* */
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void ConcurrentIncrementalSmoother::print(const std::string& s, const KeyFormatter& keyFormatter) const {
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  std::cout << s;
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  isam2_.print("");
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}
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/* ************************************************************************* */
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bool ConcurrentIncrementalSmoother::equals(const ConcurrentSmoother& rhs, double tol) const {
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  const ConcurrentIncrementalSmoother* smoother = dynamic_cast<const ConcurrentIncrementalSmoother*>(&rhs);
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  return smoother
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      && isam2_.equals(smoother->isam2_)
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      && smootherFactors_.equals(smoother->smootherFactors_)
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      && smootherValues_.equals(smoother->smootherValues_)
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      && filterSummarizationFactors_.equals(smoother->filterSummarizationFactors_)
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      && separatorValues_.equals(smoother->separatorValues_)
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      && (filterSummarizationSlots_.size() == smoother->filterSummarizationSlots_.size())
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      && std::equal(filterSummarizationSlots_.begin(), filterSummarizationSlots_.end(), smoother->filterSummarizationSlots_.begin())
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      && smootherSummarization_.equals(smoother->smootherSummarization_);
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}
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/* ************************************************************************* */
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ConcurrentIncrementalSmoother::Result ConcurrentIncrementalSmoother::update(const NonlinearFactorGraph& newFactors, const Values& newTheta,
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    const boost::optional<FactorIndices>& removeFactorIndices) {
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  gttic(update);
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  // Create the return result meta-data
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  Result result;
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  FastVector<size_t> removedFactors;
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  if(removeFactorIndices){
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    // Be very careful to this line
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    std::cout << "ConcurrentIncrementalSmoother::update    removeFactorIndices - not implemented yet" << std::endl;
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    filterSummarizationSlots_.insert(filterSummarizationSlots_.end(), removeFactorIndices->begin(), removeFactorIndices->end());
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    // before it was:
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    //  removedFactors.insert(removedFactors.end(), removeFactorIndices->begin(), removeFactorIndices->end());
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  }
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  // Constrain the separator keys to remain in the root
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  // Also, mark the separator keys as fixed linearization points
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  FastMap<Key,int> constrainedKeys;
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  FastList<Key> noRelinKeys;
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  for(const Values::ConstKeyValuePair& key_value: separatorValues_) {
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    constrainedKeys[key_value.key] = 1;
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    noRelinKeys.push_back(key_value.key);
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  }
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  // Use iSAM2 to perform an update
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  ISAM2Result isam2Result;
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  if(isam2_.getFactorsUnsafe().size() + newFactors.size() + smootherFactors_.size() + filterSummarizationFactors_.size() > 0) {
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    if(synchronizationUpdatesAvailable_) {
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      // Augment any new factors/values with the cached data from the last synchronization
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      NonlinearFactorGraph graph(newFactors);
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      graph.push_back(smootherFactors_);
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      graph.push_back(filterSummarizationFactors_);
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      Values values(newTheta);
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      // Unfortunately, we must be careful here, as some of the smoother values
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      // and/or separator values may have been added previously
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      for(const Values::ConstKeyValuePair& key_value: smootherValues_) {
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        if(!isam2_.getLinearizationPoint().exists(key_value.key)) {
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          values.insert(key_value.key, smootherValues_.at(key_value.key));
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        }
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      }
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      for(const Values::ConstKeyValuePair& key_value: separatorValues_) {
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        if(!isam2_.getLinearizationPoint().exists(key_value.key)) {
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          values.insert(key_value.key, separatorValues_.at(key_value.key));
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        }
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      }
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      // Update the system using iSAM2
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      isam2Result = isam2_.update(graph, values, filterSummarizationSlots_, constrainedKeys, noRelinKeys);
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      // Clear out the cache and update the filter summarization slots
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      smootherFactors_.resize(0);
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      smootherValues_.clear();
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      filterSummarizationSlots_.clear();
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      filterSummarizationSlots_.insert(filterSummarizationSlots_.end(),
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          isam2Result.newFactorsIndices.end()-filterSummarizationFactors_.size(), isam2Result.newFactorsIndices.end());
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      filterSummarizationFactors_.resize(0);
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      synchronizationUpdatesAvailable_ = false;
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    } else {
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      // Update the system using iSAM2
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      isam2Result = isam2_.update(newFactors, newTheta, FactorIndices(), constrainedKeys, noRelinKeys);
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    }
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  }
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  // Extract the ConcurrentIncrementalSmoother::Result information
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  result.iterations = 1;
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  result.linearVariables = separatorValues_.size();
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  result.nonlinearVariables = isam2_.getLinearizationPoint().size() - separatorValues_.size();
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  result.error = isam2_.getFactorsUnsafe().error(isam2_.calculateEstimate());
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  // Calculate the marginal on the separator from the smoother factors
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  if(separatorValues_.size() > 0) {
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    gttic(presync);
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    updateSmootherSummarization();
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    gttoc(presync);
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  }
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  gttoc(update);
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  return result;
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}
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/* ************************************************************************* */
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void ConcurrentIncrementalSmoother::presync() {
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  gttic(presync);
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  gttoc(presync);
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}
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/* ************************************************************************* */
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void ConcurrentIncrementalSmoother::getSummarizedFactors(NonlinearFactorGraph& summarizedFactors, Values& separatorValues) {
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  gttic(get_summarized_factors);
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  // Copy the previous calculated smoother summarization factors into the output
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  summarizedFactors.push_back(smootherSummarization_);
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  // Copy the separator values into the output
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  separatorValues.insert(separatorValues_);
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  gttoc(get_summarized_factors);
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}
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/* ************************************************************************* */
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void ConcurrentIncrementalSmoother::synchronize(const NonlinearFactorGraph& smootherFactors, const Values& smootherValues,
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    const NonlinearFactorGraph& summarizedFactors, const Values& separatorValues) {
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  gttic(synchronize);
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  // Store the new smoother factors and values for addition during the next update call
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  smootherFactors_ = smootherFactors;
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  smootherValues_ = smootherValues;
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  // Store the new filter summarization and separator, to be replaced during the next update call
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  filterSummarizationFactors_ = summarizedFactors;
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  separatorValues_ = separatorValues;
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  // Flag the next smoother update to include the synchronization data
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  synchronizationUpdatesAvailable_ = true;
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  gttoc(synchronize);
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}
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/* ************************************************************************* */
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void ConcurrentIncrementalSmoother::postsync() {
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  gttic(postsync);
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  gttoc(postsync);
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}
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/* ************************************************************************* */
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void ConcurrentIncrementalSmoother::updateSmootherSummarization() {
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  // The smoother summarization factors are the resulting marginal factors on the separator
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  // variables that result from marginalizing out all of the other variables
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  // These marginal factors will be cached for later transmission to the filter using
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  // linear container factors
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  // Find all cliques that contain any separator variables
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  std::set<ISAM2Clique::shared_ptr> separatorCliques;
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  for(Key key: separatorValues_.keys()) {
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    ISAM2Clique::shared_ptr clique = isam2_[key];
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    separatorCliques.insert( clique );
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  }
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  // Create the set of clique keys LC:
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  KeyVector cliqueKeys;
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  for(const ISAM2Clique::shared_ptr& clique: separatorCliques) {
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    for(Key key: clique->conditional()->frontals()) {
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      cliqueKeys.push_back(key);
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    }
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  }
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  std::sort(cliqueKeys.begin(), cliqueKeys.end());
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  // Gather all factors that involve only clique keys
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  std::set<size_t> cliqueFactorSlots;
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  for(Key key: cliqueKeys) {
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    for(size_t slot: isam2_.getVariableIndex()[key]) {
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      const NonlinearFactor::shared_ptr& factor = isam2_.getFactorsUnsafe().at(slot);
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      if(factor) {
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        std::set<Key> factorKeys(factor->begin(), factor->end());
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        if(std::includes(cliqueKeys.begin(), cliqueKeys.end(), factorKeys.begin(), factorKeys.end())) {
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          cliqueFactorSlots.insert(slot);
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        }
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      }
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    }
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  }
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  // Remove any factor included in the filter summarization
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  for(size_t slot: filterSummarizationSlots_) {
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    cliqueFactorSlots.erase(slot);
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  }
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  // Create a factor graph from the identified factors
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  NonlinearFactorGraph graph;
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  for(size_t slot: cliqueFactorSlots) {
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    graph.push_back(isam2_.getFactorsUnsafe().at(slot));
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  }
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  // Find the set of children of the separator cliques
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  std::set<ISAM2Clique::shared_ptr> childCliques;
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  // Add all of the children
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  for(const ISAM2Clique::shared_ptr& clique: separatorCliques) {
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    childCliques.insert(clique->children.begin(), clique->children.end());
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  }
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  // Remove any separator cliques that were added because they were children of other separator cliques
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  for(const ISAM2Clique::shared_ptr& clique: separatorCliques) {
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    childCliques.erase(clique);
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  }
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  // Augment the factor graph with cached factors from the children
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  for(const ISAM2Clique::shared_ptr& clique: childCliques) {
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    LinearContainerFactor::shared_ptr factor(new LinearContainerFactor(clique->cachedFactor(), isam2_.getLinearizationPoint()));
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    graph.push_back( factor );
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  }
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  // Get the set of separator keys
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  KeySet separatorKeys;
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  for(const Values::ConstKeyValuePair& key_value: separatorValues_) {
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    separatorKeys.insert(key_value.key);
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  }
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  // Calculate the marginal factors on the separator
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  smootherSummarization_ = internal::calculateMarginalFactors(graph, isam2_.getLinearizationPoint(), separatorKeys,
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      isam2_.params().getEliminationFunction());
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}
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/* ************************************************************************* */
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}/// namespace gtsam
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