395 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			395 lines
		
	
	
		
			15 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  BetweenFactorEM.h
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 *  @author Vadim Indelman
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 **/
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#pragma once
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#include <ostream>
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#include <gtsam/base/Testable.h>
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#include <gtsam/base/Lie.h>
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#include <gtsam/nonlinear/NonlinearFactor.h>
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#include <gtsam/linear/GaussianFactor.h>
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#include <gtsam/nonlinear/Marginals.h>
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namespace gtsam {
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  /**
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   * A class for a measurement predicted by "between(config[key1],config[key2])"
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   * @tparam VALUE the Value type
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   * @addtogroup SLAM
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   */
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  template<class VALUE>
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  class BetweenFactorEM: public NonlinearFactor {
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  public:
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    typedef VALUE T;
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  private:
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    typedef BetweenFactorEM<VALUE> This;
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    typedef gtsam::NonlinearFactor Base;
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    gtsam::Key key1_;
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    gtsam::Key key2_;
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    VALUE measured_; /** The measurement */
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    SharedGaussian model_inlier_;
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    SharedGaussian model_outlier_;
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    double prior_inlier_;
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    double prior_outlier_;
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    bool flag_bump_up_near_zero_probs_;
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    /** concept check by type */
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    GTSAM_CONCEPT_LIE_TYPE(T)
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    GTSAM_CONCEPT_TESTABLE_TYPE(T)
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  public:
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    // shorthand for a smart pointer to a factor
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    typedef typename boost::shared_ptr<BetweenFactorEM> shared_ptr;
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    /** default constructor - only use for serialization */
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    BetweenFactorEM() {}
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    /** Constructor */
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    BetweenFactorEM(Key key1, Key key2, const VALUE& measured,
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        const SharedGaussian& model_inlier, const SharedGaussian& model_outlier,
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        const double prior_inlier, const double prior_outlier, const bool flag_bump_up_near_zero_probs = false) :
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          Base(cref_list_of<2>(key1)(key2)), key1_(key1), key2_(key2), measured_(measured),
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          model_inlier_(model_inlier), model_outlier_(model_outlier),
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          prior_inlier_(prior_inlier), prior_outlier_(prior_outlier), flag_bump_up_near_zero_probs_(flag_bump_up_near_zero_probs){
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    }
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    virtual ~BetweenFactorEM() {}
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    /** implement functions needed for Testable */
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    /** print */
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    virtual void print(const std::string& s, const KeyFormatter& keyFormatter = DefaultKeyFormatter) const {
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      std::cout << s << "BetweenFactorEM("
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          << keyFormatter(key1_) << ","
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          << keyFormatter(key2_) << ")\n";
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      measured_.print("  measured: ");
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      model_inlier_->print("  noise model inlier: ");
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      model_outlier_->print("  noise model outlier: ");
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      std::cout << "(prior_inlier, prior_outlier_) = ("
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                << prior_inlier_ << ","
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                << prior_outlier_ << ")\n";
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      //      Base::print(s, keyFormatter);
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    }
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    /** equals */
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    virtual bool equals(const NonlinearFactor& f, double tol=1e-9) const {
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      const This *t =  dynamic_cast<const This*> (&f);
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      if(t && Base::equals(f))
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        return key1_ == t->key1_ && key2_ == t->key2_ &&
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            //            model_inlier_->equals(t->model_inlier_ ) && // TODO: fix here
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            //            model_outlier_->equals(t->model_outlier_ ) &&
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            prior_outlier_ == t->prior_outlier_ && prior_inlier_ == t->prior_inlier_ && measured_.equals(t->measured_);
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      else
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        return false;
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    }
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    /** implement functions needed to derive from Factor */
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    /* ************************************************************************* */
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    virtual double error(const gtsam::Values& x) const {
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      return whitenedError(x).squaredNorm();
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    }
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    /* ************************************************************************* */
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    /**
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     * Linearize a non-linearFactorN to get a gtsam::GaussianFactor,
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     * \f$ Ax-b \approx h(x+\delta x)-z = h(x) + A \delta x - z \f$
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     * Hence \f$ b = z - h(x) = - \mathtt{error\_vector}(x) \f$
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     */
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    /* This version of linearize recalculates the noise model each time */
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    virtual boost::shared_ptr<gtsam::GaussianFactor> linearize(const gtsam::Values& x) const {
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      // Only linearize if the factor is active
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      if (!this->active(x))
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        return boost::shared_ptr<gtsam::JacobianFactor>();
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      //std::cout<<"About to linearize"<<std::endl;
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      gtsam::Matrix A1, A2;
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      std::vector<gtsam::Matrix> A(this->size());
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      gtsam::Vector b = -whitenedError(x, A);
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      A1 = A[0];
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      A2 = A[1];
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      return gtsam::GaussianFactor::shared_ptr(
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          new gtsam::JacobianFactor(key1_, A1, key2_, A2, b, gtsam::noiseModel::Unit::Create(b.size())));
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    }
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    /* ************************************************************************* */
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    gtsam::Vector whitenedError(const gtsam::Values& x,
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        boost::optional<std::vector<gtsam::Matrix>&> H = boost::none) const {
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      bool debug = true;
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      const T& p1 = x.at<T>(key1_);
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      const T& p2 = x.at<T>(key2_);
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      Matrix H1, H2;
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      T hx = p1.between(p2, H1, H2); // h(x)
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      // manifold equivalent of h(x)-z -> log(z,h(x))
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      Vector err = measured_.localCoordinates(hx);
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      // Calculate indicator probabilities (inlier and outlier)
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      Vector p_inlier_outlier = calcIndicatorProb(x);
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      double p_inlier  = p_inlier_outlier[0];
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      double p_outlier = p_inlier_outlier[1];
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      Vector err_wh_inlier  = model_inlier_->whiten(err);
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      Vector err_wh_outlier = model_outlier_->whiten(err);
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      Matrix invCov_inlier  = model_inlier_->R().transpose() * model_inlier_->R();
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      Matrix invCov_outlier = model_outlier_->R().transpose() * model_outlier_->R();
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      Vector err_wh_eq;
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      err_wh_eq.resize(err_wh_inlier.rows()*2);
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      err_wh_eq << sqrt(p_inlier) * err_wh_inlier.array() , sqrt(p_outlier) * err_wh_outlier.array();
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      if (H){
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        // stack Jacobians for the two indicators for each of the key
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        Matrix H1_inlier  = sqrt(p_inlier)*model_inlier_->Whiten(H1);
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        Matrix H1_outlier = sqrt(p_outlier)*model_outlier_->Whiten(H1);
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        Matrix H1_aug = gtsam::stack(2, &H1_inlier, &H1_outlier);
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        Matrix H2_inlier  = sqrt(p_inlier)*model_inlier_->Whiten(H2);
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        Matrix H2_outlier = sqrt(p_outlier)*model_outlier_->Whiten(H2);
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        Matrix H2_aug = gtsam::stack(2, &H2_inlier, &H2_outlier);
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        (*H)[0].resize(H1_aug.rows(),H1_aug.cols());
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        (*H)[1].resize(H2_aug.rows(),H2_aug.cols());
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        (*H)[0] = H1_aug;
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        (*H)[1] = H2_aug;
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      }
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      if (debug){
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        //        std::cout<<"unwhitened error: "<<err[0]<<" "<<err[1]<<" "<<err[2]<<std::endl;
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        //        std::cout<<"err_wh_inlier: "<<err_wh_inlier[0]<<" "<<err_wh_inlier[1]<<" "<<err_wh_inlier[2]<<std::endl;
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        //        std::cout<<"err_wh_outlier: "<<err_wh_outlier[0]<<" "<<err_wh_outlier[1]<<" "<<err_wh_outlier[2]<<std::endl;
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        //
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        //        std::cout<<"p_inlier, p_outlier, sumP: "<<p_inlier<<" "<<p_outlier<<" " << sumP << std::endl;
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        //
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        //        std::cout<<"prior_inlier_, prior_outlier_: "<<prior_inlier_<<" "<<prior_outlier_<< std::endl;
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        //
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        //        double s_inl  = -0.5 * err_wh_inlier.dot(err_wh_inlier);
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        //        double s_outl = -0.5 * err_wh_outlier.dot(err_wh_outlier);
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        //        std::cout<<"s_inl, s_outl: "<<s_inl<<" "<<s_outl<<std::endl;
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        //
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        //        std::cout<<"norm of invCov_inlier, invCov_outlier: "<<invCov_inlier.norm()<<" "<<invCov_outlier.norm()<<std::endl;
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        //        double q_inl  = invCov_inlier.norm() * exp( -0.5 * err_wh_inlier.dot(err_wh_inlier) );
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        //        double q_outl = invCov_outlier.norm() * exp( -0.5 * err_wh_outlier.dot(err_wh_outlier) );
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        //        std::cout<<"q_inl, q_outl: "<<q_inl<<" "<<q_outl<<std::endl;
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        //        Matrix Cov_inlier  = invCov_inlier.inverse();
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        //        Matrix Cov_outlier = invCov_outlier.inverse();
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        //        std::cout<<"Cov_inlier: "<<std::endl<<
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        //            Cov_inlier(0,0) << " " << Cov_inlier(0,1) << " " << Cov_inlier(0,2) <<std::endl<<
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        //            Cov_inlier(1,0) << " " << Cov_inlier(1,1) << " " << Cov_inlier(1,2) <<std::endl<<
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        //            Cov_inlier(2,0) << " " << Cov_inlier(2,1) << " " << Cov_inlier(2,2) <<std::endl;
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        //        std::cout<<"Cov_outlier: "<<std::endl<<
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        //                    Cov_outlier(0,0) << " " << Cov_outlier(0,1) << " " << Cov_outlier(0,2) <<std::endl<<
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        //                    Cov_outlier(1,0) << " " << Cov_outlier(1,1) << " " << Cov_outlier(1,2) <<std::endl<<
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        //                    Cov_outlier(2,0) << " " << Cov_outlier(2,1) << " " << Cov_outlier(2,2) <<std::endl;
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        //        std::cout<<"===="<<std::endl;
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      }
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      return err_wh_eq;
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    }
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    /* ************************************************************************* */
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    gtsam::Vector calcIndicatorProb(const gtsam::Values& x) const {
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      bool debug = false;
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      Vector err =  unwhitenedError(x);
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      // Calculate indicator probabilities (inlier and outlier)
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      Vector err_wh_inlier  = model_inlier_->whiten(err);
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      Vector err_wh_outlier = model_outlier_->whiten(err);
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      Matrix invCov_inlier  = model_inlier_->R().transpose() * model_inlier_->R();
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      Matrix invCov_outlier = model_outlier_->R().transpose() * model_outlier_->R();
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      double p_inlier  = prior_inlier_ * std::sqrt(invCov_inlier.norm()) * exp( -0.5 * err_wh_inlier.dot(err_wh_inlier) );
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      double p_outlier = prior_outlier_ * std::sqrt(invCov_outlier.norm()) * exp( -0.5 * err_wh_outlier.dot(err_wh_outlier) );
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      if (debug){
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        std::cout<<"in calcIndicatorProb. err_unwh: "<<err[0]<<", "<<err[1]<<", "<<err[2]<<std::endl;
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        std::cout<<"in calcIndicatorProb. err_wh_inlier: "<<err_wh_inlier[0]<<", "<<err_wh_inlier[1]<<", "<<err_wh_inlier[2]<<std::endl;
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        std::cout<<"in calcIndicatorProb. err_wh_inlier.dot(err_wh_inlier): "<<err_wh_inlier.dot(err_wh_inlier)<<std::endl;
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        std::cout<<"in calcIndicatorProb. err_wh_outlier.dot(err_wh_outlier): "<<err_wh_outlier.dot(err_wh_outlier)<<std::endl;
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        std::cout<<"in calcIndicatorProb. p_inlier, p_outlier before normalization: "<<p_inlier<<", "<<p_outlier<<std::endl;
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      }
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      double sumP = p_inlier + p_outlier;
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      p_inlier  /= sumP;
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      p_outlier /= sumP;
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      if (flag_bump_up_near_zero_probs_){
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        // Bump up near-zero probabilities (as in linerFlow.h)
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        double minP = 0.05; // == 0.1 / 2 indicator variables
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        if (p_inlier < minP || p_outlier < minP){
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          if (p_inlier < minP)
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            p_inlier = minP;
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          if (p_outlier < minP)
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            p_outlier = minP;
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          sumP = p_inlier + p_outlier;
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          p_inlier  /= sumP;
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          p_outlier /= sumP;
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        }
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      }
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      return (Vector(2) << p_inlier, p_outlier);
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    }
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    /* ************************************************************************* */
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    gtsam::Vector unwhitenedError(const gtsam::Values& x) const {
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      const T& p1 = x.at<T>(key1_);
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      const T& p2 = x.at<T>(key2_);
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      Matrix H1, H2;
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      T hx = p1.between(p2, H1, H2); // h(x)
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      return measured_.localCoordinates(hx);
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    }
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    /* ************************************************************************* */
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    void set_flag_bump_up_near_zero_probs(bool flag) {
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      flag_bump_up_near_zero_probs_ = flag;
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    }
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    /* ************************************************************************* */
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    bool get_flag_bump_up_near_zero_probs() const {
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      return flag_bump_up_near_zero_probs_;
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    }
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    /* ************************************************************************* */
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    SharedGaussian get_model_inlier() const {
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    	return model_inlier_;
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    }
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    /* ************************************************************************* */
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    SharedGaussian get_model_outlier() const {
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    	return model_outlier_;
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    }
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    /* ************************************************************************* */
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    Matrix get_model_inlier_cov() const {
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    	return (model_inlier_->R().transpose()*model_inlier_->R()).inverse();
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    }
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    /* ************************************************************************* */
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    Matrix get_model_outlier_cov() const {
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    	return (model_outlier_->R().transpose()*model_outlier_->R()).inverse();
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    }
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    /* ************************************************************************* */
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    void updateNoiseModels(const gtsam::Values& values, const gtsam::NonlinearFactorGraph& graph){
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    	/* Update model_inlier_ and model_outlier_ to account for uncertainty in robot trajectories
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    	 * (note these are given in the E step, where indicator probabilities are calculated).
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    	 *
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    	 * Principle: R += [H1 H2] * joint_cov12 * [H1 H2]', where H1, H2 are Jacobians of the
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    	 * unwhitened error w.r.t. states, and R is the measurement covariance (inlier or outlier modes).
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    	 *
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    	 * TODO: improve efficiency (info form)
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    	 */
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    	 const T& p1 = values.at<T>(key1_);
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    	 const T& p2 = values.at<T>(key2_);
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    	 Matrix H1, H2;
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    	 T hx = p1.between(p2, H1, H2); // h(x)
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    	 // get joint covariance of the involved states
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    	 std::vector<gtsam::Key> Keys;
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    	 Keys.push_back(key1_);
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    	 Keys.push_back(key2_);
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    	 Marginals marginals( graph, values, Marginals::QR );
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    	 JointMarginal joint_marginal12 = marginals.jointMarginalCovariance(Keys);
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    	 Matrix cov1 = joint_marginal12(key1_, key1_);
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    	 Matrix cov2 = joint_marginal12(key2_, key2_);
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    	 Matrix cov12 = joint_marginal12(key1_, key2_);
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    	 Matrix H;
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    	 H.resize(H1.rows(), H1.rows()+H2.rows());
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    	 H << H1, H2; // H = [H1 H2]
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    	 Matrix joint_cov;
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    	 joint_cov.resize(cov1.rows()+cov2.rows(), cov1.cols()+cov2.cols());
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    	 joint_cov << cov1, cov12,
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    			 cov12.transpose(), cov2;
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    	 Matrix cov_state = H*joint_cov*H.transpose();
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    	 //    	 model_inlier_->print("before:");
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    	 // update inlier and outlier noise models
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    	 Matrix covRinlier = (model_inlier_->R().transpose()*model_inlier_->R()).inverse();
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    	 model_inlier_ = gtsam::noiseModel::Gaussian::Covariance(covRinlier + cov_state);
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    	 Matrix covRoutlier = (model_outlier_->R().transpose()*model_outlier_->R()).inverse();
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    	 model_outlier_ = gtsam::noiseModel::Gaussian::Covariance(covRoutlier + cov_state);
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    	 //    	 model_inlier_->print("after:");
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    	 //    	 std::cout<<"covRinlier + cov_state: "<<covRinlier + cov_state<<std::endl;
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    }
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    /* ************************************************************************* */
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    /** return the measured */
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    const VALUE& measured() const {
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      return measured_;
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    }
 | 
						|
 | 
						|
    /** number of variables attached to this factor */
 | 
						|
    std::size_t size() const {
 | 
						|
      return 2;
 | 
						|
    }
 | 
						|
 | 
						|
    virtual size_t dim() const {
 | 
						|
      return model_inlier_->R().rows() + model_inlier_->R().cols();
 | 
						|
    }
 | 
						|
 | 
						|
  private:
 | 
						|
 | 
						|
    /** Serialization function */
 | 
						|
    friend class boost::serialization::access;
 | 
						|
    template<class ARCHIVE>
 | 
						|
    void serialize(ARCHIVE & ar, const unsigned int version) {
 | 
						|
      ar & boost::serialization::make_nvp("NonlinearFactor",
 | 
						|
          boost::serialization::base_object<Base>(*this));
 | 
						|
      ar & BOOST_SERIALIZATION_NVP(measured_);
 | 
						|
    }
 | 
						|
  }; // \class BetweenFactorEM
 | 
						|
 | 
						|
} /// namespace gtsam
 |