259 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			259 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
| /* ----------------------------------------------------------------------------
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| 
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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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| 
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|  * See LICENSE for the license information
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| 
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|  * -------------------------------------------------------------------------- */
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| 
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| /**
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|  * @file    ConcurrentBatchSmoother.h
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|  * @brief   A Levenberg-Marquardt Batch 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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| 
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| // \callgraph
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| #pragma once
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| 
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| #include <gtsam_unstable/nonlinear/ConcurrentFilteringAndSmoothing.h>
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| #include <gtsam/nonlinear/LevenbergMarquardtOptimizer.h>
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| #include <queue>
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| 
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| namespace gtsam {
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| 
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| /**
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|  * A Levenberg-Marquardt Batch Smoother that implements the Concurrent Filtering and Smoother interface.
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|  */
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| class GTSAM_UNSTABLE_EXPORT ConcurrentBatchSmoother : public ConcurrentSmoother {
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| 
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| public:
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|   typedef boost::shared_ptr<ConcurrentBatchSmoother> shared_ptr;
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|   typedef ConcurrentSmoother Base; ///< typedef for base class
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| 
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|   /** Meta information returned about the update */
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|   struct Result {
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|     size_t iterations; ///< The number of optimizer iterations performed
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|     size_t lambdas; ///< The number of different L-M lambda factors that were tried during optimization
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|     size_t nonlinearVariables; ///< The number of variables that can be relinearized
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|     size_t linearVariables; ///< The number of variables that must keep a constant linearization point
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|     double error; ///< The final factor graph error
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| 
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|     /// Constructor
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|     Result() : iterations(0), lambdas(0), nonlinearVariables(0), linearVariables(0), error(0) {};
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| 
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|     /// Getter methods
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|     size_t getIterations() const { return iterations; }
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|     size_t getLambdas() const { return lambdas; }
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|     size_t getNonlinearVariables() const { return nonlinearVariables; }
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|     size_t getLinearVariables() const { return linearVariables; }
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|     double getError() const { return error; }
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|   };
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| 
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|   /** Default constructor */
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|   ConcurrentBatchSmoother(const LevenbergMarquardtParams& parameters = LevenbergMarquardtParams()) : parameters_(parameters) {};
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| 
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|   /** Default destructor */
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|   virtual ~ConcurrentBatchSmoother() {};
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| 
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|   /** Implement a GTSAM standard 'print' function */
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|   void print(const std::string& s = "Concurrent Batch Smoother:\n", const KeyFormatter& keyFormatter = DefaultKeyFormatter) const;
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| 
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|   /** Check if two Concurrent Smoothers are equal */
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|   bool equals(const ConcurrentSmoother& rhs, double tol = 1e-9) const;
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| 
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|   /** Access the current set of factors */
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|   const NonlinearFactorGraph& getFactors() const {
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|     return factors_;
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|   }
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| 
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|   /** Access the current linearization point */
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|   const Values& getLinearizationPoint() const {
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|     return theta_;
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|   }
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| 
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|   /** Access the current ordering */
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|   const Ordering& getOrdering() const {
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|     return ordering_;
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|   }
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| 
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|   /** Access the current set of deltas to the linearization point */
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|   const VectorValues& getDelta() const {
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|     return delta_;
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|   }
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| 
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|   /** Compute the current best estimate of all variables and return a full Values structure.
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|    * If only a single variable is needed, it may be faster to call calculateEstimate(const KEY&).
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|    */
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|   Values calculateEstimate() const {
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|     return theta_.retract(delta_, ordering_);
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|   }
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| 
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|   /** Compute the current best estimate of a single variable. This is generally faster than
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|    * calling the no-argument version of calculateEstimate if only specific variables are needed.
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|    * @param key
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|    * @return
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|    */
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|   template<class VALUE>
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|   VALUE calculateEstimate(Key key) const {
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|     const Index index = ordering_.at(key);
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|     const Vector delta = delta_.at(index);
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|     return theta_.at<VALUE>(key).retract(delta);
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|   }
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| 
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|   /**
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|    * Add new factors and variables to the smoother.
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|    *
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|    * Add new measurements, and optionally new variables, to the smoother.
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|    * This runs a full step of the ISAM2 algorithm, relinearizing and updating
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|    * the solution as needed, according to the wildfire and relinearize
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|    * thresholds.
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|    *
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|    * @param newFactors The new factors to be added to the smoother
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|    * @param newTheta Initialization points for new variables to be added to the smoother
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|    * You must include here all new variables occuring in newFactors (which were not already
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|    * in the smoother).  There must not be any variables here that do not occur in newFactors,
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|    * and additionally, variables that were already in the system must not be included here.
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|    */
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|   Result update(const NonlinearFactorGraph& newFactors = NonlinearFactorGraph(), const Values& newTheta = Values());
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| 
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| 
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| protected:
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| 
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|   LevenbergMarquardtParams parameters_;  ///< LM parameters
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|   NonlinearFactorGraph factors_;  ///< The set of all factors currently in the smoother
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|   Values theta_;  ///< Current linearization point of all variables in the smoother
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|   Ordering ordering_; ///< The current ordering used to calculate the linear deltas
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|   VectorValues delta_; ///< The current set of linear deltas from the linearization point
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|   VariableIndex variableIndex_; ///< The current variable index, which allows efficient factor lookup by variable
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|   std::queue<size_t> availableSlots_; ///< The set of available factor graph slots caused by deleting factors
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|   Values separatorValues_; ///< The linearization points of the separator variables. These should not be updated during optimization.
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|   std::vector<size_t> filterSummarizationSlots_;  ///< The slots in factor graph that correspond to the current filter summarization factors
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| 
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|   // Storage for information to be sent to the filter
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|   NonlinearFactorGraph smootherSummarization_; ///< A temporary holding place for calculated smoother summarization
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| 
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|   /**
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|    * Perform any required operations before the synchronization process starts.
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|    * Called by 'synchronize'
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|    */
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|   virtual void presync();
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| 
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|   /**
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|    * Populate the provided containers with factors that constitute the smoother branch summarization
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|    * needed by the filter.
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|    *
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|    * @param summarizedFactors The summarized factors for the filter branch
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|    */
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|   virtual void getSummarizedFactors(NonlinearFactorGraph& summarizedFactors, Values& separatorValues);
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| 
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|   /**
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|    * Apply the new smoother factors sent by the filter, and the updated version of the filter
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|    * branch summarized factors.
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|    *
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|    * @param smootherFactors A set of new factors added to the smoother from the filter
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|    * @param smootherValues Linearization points for any new variables
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|    * @param summarizedFactors An updated version of the filter branch summarized factors
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|    * @param rootValues The linearization point of the root variables
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|    */
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|   virtual void synchronize(const NonlinearFactorGraph& smootherFactors, const Values& smootherValues,
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|       const NonlinearFactorGraph& summarizedFactors, const Values& separatorValues);
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| 
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|   /**
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|    * Perform any required operations after the synchronization process finishes.
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|    * Called by 'synchronize'
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|    */
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|   virtual void postsync();
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| 
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| private:
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| 
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|   /** Augment the graph with new factors
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|    *
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|    * @param factors The factors to add to the graph
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|    * @return The slots in the graph where they were inserted
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|    */
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|   std::vector<size_t> insertFactors(const NonlinearFactorGraph& factors);
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| 
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|   /** Remove factors from the graph by slot index
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|    *
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|    * @param slots The slots in the factor graph that should be deleted
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|    * */
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|   void removeFactors(const std::vector<size_t>& slots);
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| 
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|   /** Use colamd to update into an efficient ordering */
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|   void reorder();
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| 
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|   /** Use a modified version of L-M to update the linearization point and delta */
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|   Result optimize();
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| 
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|   /** Calculate the smoother marginal factors on the separator variables */
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|   void updateSmootherSummarization();
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| 
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|   /** Print just the nonlinear keys in a nonlinear factor */
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|   static void PrintNonlinearFactor(const NonlinearFactor::shared_ptr& factor,
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|       const std::string& indent = "", const KeyFormatter& keyFormatter = DefaultKeyFormatter);
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| 
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|   /** Print just the nonlinear keys in a linear factor */
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|   static void PrintLinearFactor(const GaussianFactor::shared_ptr& factor, const Ordering& ordering,
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|       const std::string& indent = "", const KeyFormatter& keyFormatter = DefaultKeyFormatter);
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| 
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|   // A custom elimination tree that supports forests and partial elimination
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|   class EliminationForest {
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|   public:
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|     typedef boost::shared_ptr<EliminationForest> shared_ptr; ///< Shared pointer to this class
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| 
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|   private:
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|     typedef FastList<GaussianFactor::shared_ptr> Factors;
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|     typedef FastList<shared_ptr> SubTrees;
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|     typedef std::vector<GaussianConditional::shared_ptr> Conditionals;
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| 
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|     Index key_; ///< index associated with root
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|     Factors factors_; ///< factors associated with root
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|     SubTrees subTrees_; ///< sub-trees
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| 
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|     /** default constructor, private, as you should use Create below */
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|     EliminationForest(Index key = 0) : key_(key) {}
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| 
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|     /**
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|      * Static internal function to build a vector of parent pointers using the
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|      * algorithm of Gilbert et al., 2001, BIT.
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|      */
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|     static std::vector<Index> ComputeParents(const VariableIndex& structure);
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| 
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|     /** add a factor, for Create use only */
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|     void add(const GaussianFactor::shared_ptr& factor) { factors_.push_back(factor); }
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| 
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|     /** add a subtree, for Create use only */
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|     void add(const shared_ptr& child) { subTrees_.push_back(child); }
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| 
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|   public:
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| 
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|     /** return the key associated with this tree node */
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|     Index key() const { return key_; }
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| 
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|     /** return the const reference of children */
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|     const SubTrees& children() const { return subTrees_; }
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| 
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|     /** return the const reference to the factors */
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|     const Factors& factors() const { return factors_; }
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| 
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|     /** Create an elimination tree from a factor graph */
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|     static std::vector<shared_ptr> Create(const GaussianFactorGraph& factorGraph, const VariableIndex& structure);
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| 
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|     /** Recursive routine that eliminates the factors arranged in an elimination tree */
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|     GaussianFactor::shared_ptr eliminateRecursive(GaussianFactorGraph::Eliminate function);
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| 
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|     /** Recursive function that helps find the top of each tree */
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|     static void removeChildrenIndices(std::set<Index>& indices, const EliminationForest::shared_ptr& tree);
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|   };
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| 
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| }; // ConcurrentBatchSmoother
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| 
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| /// Typedef for Matlab wrapping
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| typedef ConcurrentBatchSmoother::Result ConcurrentBatchSmootherResult;
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| 
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| }/// namespace gtsam
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