gridslamprocessor_tree.cpp

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#include <string>
#include <deque>
#include <list>
#include <map>
#include <set>
#include <fstream>
//#include <gsl/gsl_blas.h>

#include <gmapping/utils/stat.h>
#include "gmapping/gridfastslam/gridslamprocessor.h"

namespace GMapping {

using namespace std;

GridSlamProcessor::TNode::TNode(const OrientedPoint& p, double w, TNode* n, unsigned int c){
        pose=p;
        weight=w;
        childs=c;
        parent=n;
        reading=0;
        gweight=0;
        if (n){
                n->childs++;
        }
        flag=0;
        accWeight=0;
}


GridSlamProcessor::TNode::~TNode(){
        if (parent && (--parent->childs)<=0)
                delete parent;
        assert(!childs);
}


//BEGIN State Save/Restore

GridSlamProcessor::TNodeVector GridSlamProcessor::getTrajectories() const{
  TNodeVector v;
  TNodeMultimap parentCache;
  TNodeDeque border;
        
        for (ParticleVector::const_iterator it=m_particles.begin(); it!=m_particles.end(); it++){
                TNode* node=it->node;
                while(node){
                        node->flag=false;
                        node=node->parent;
                }
        }
        
        for (ParticleVector::const_iterator it=m_particles.begin(); it!=m_particles.end(); it++){
                TNode* newnode=new TNode(* (it->node) );
                
                v.push_back(newnode);
                assert(newnode->childs==0);
                if (newnode->parent){
                        parentCache.insert(make_pair(newnode->parent, newnode));
                        //cerr << __func__ << ": node " << newnode->parent << " flag=" << newnode->parent->flag<< endl;
                        if (! newnode->parent->flag){
                                //cerr << __func__ << ": node " << newnode->parent << " flag=" << newnode->parent->flag<< endl;
                                newnode->parent->flag=true;
                                border.push_back(newnode->parent);
                        }
                }
        }
        
        //cerr << __func__ << ": border.size(INITIAL)=" << border.size() << endl;
        //cerr << __func__ << ": parentCache.size()=" << parentCache.size() << endl;
        while (! border.empty()){
                //cerr << __func__ << ": border.size(PREPROCESS)=" << border.size() << endl;
                //cerr << __func__ << ": parentCache.size(PREPROCESS)=" << parentCache.size() << endl;
                const TNode* node=border.front();
                //cerr << __func__ << ": node " << node << endl;
                border.pop_front();
                if (! node)
                        continue;
                        
                TNode* newnode=new TNode(*node);
                node->flag=false;
                
                //update the parent of all of the referring childs 
                pair<TNodeMultimap::iterator, TNodeMultimap::iterator> p=parentCache.equal_range(node);
                double childs=0;
                for (TNodeMultimap::iterator it=p.first; it!=p.second; it++){
                        assert(it->second->parent==it->first);
                        (it->second)->parent=newnode;
                        //cerr << "PS(" << it->first << ", "<< it->second << ")";
                        childs++;
                }
                parentCache.erase(p.first, p.second);
                //cerr << __func__ << ": parentCache.size(POSTERASE)=" << parentCache.size() << endl;
                assert(childs==newnode->childs);
                
                //unmark the node
                if ( node->parent ){
                        parentCache.insert(make_pair(node->parent, newnode));
                        if(! node->parent->flag){
                                border.push_back(node->parent);
                                node->parent->flag=true;
                        }       
                }
                //insert the parent in the cache
        }
        //cerr << __func__ << " : checking cloned trajectories" << endl;
        for (unsigned int i=0; i<v.size(); i++){
                TNode* node= v[i];
                while (node){
                        //cerr <<".";
                        node=node->parent;
                }
                //cerr << endl;
        }       
        
        return v;

}

void GridSlamProcessor::integrateScanSequence(GridSlamProcessor::TNode* node){
        //reverse the list 
        TNode* aux=node;
        TNode* reversed=0;
        double count=0;
        while(aux!=0){
                TNode * newnode=new TNode(*aux);
                newnode->parent=reversed;
                reversed=newnode;
                aux=aux->parent;
                count++;
        }
        
        //attach the path to each particle and compute the map;
        if (m_infoStream )
                m_infoStream << "Restoring State Nodes=" <<count << endl;
                
                
        aux=reversed;
        bool first=true;
        double oldWeight=0;
        OrientedPoint oldPose;
        while (aux!=0){
                if (first){
                        oldPose=aux->pose;
                        first=false;
                        oldWeight=aux->weight;
                }
                
                OrientedPoint dp=aux->pose-oldPose;
                double dw=aux->weight-oldWeight;
                oldPose=aux->pose;
                
                
                double * plainReading = new double[m_beams];
                for(unsigned int i=0; i<m_beams; i++)
                        plainReading[i]=(*(aux->reading))[i];
                
                for (ParticleVector::iterator it=m_particles.begin(); it!=m_particles.end(); it++){
                        //compute the position relative to the path;
                        double s=sin(oldPose.theta-it->pose.theta),
                               c=cos(oldPose.theta-it->pose.theta);
                        
                        it->pose.x+=c*dp.x-s*dp.y;
                        it->pose.y+=s*dp.x+c*dp.y;
                        it->pose.theta+=dp.theta;
                        it->pose.theta=atan2(sin(it->pose.theta), cos(it->pose.theta));
                        
                        //register the scan
                        m_matcher.invalidateActiveArea();
                        m_matcher.computeActiveArea(it->map, it->pose, plainReading);
                        it->weight+=dw;
                        it->weightSum+=dw;

                        // this should not work, since it->weight is not the correct weight!
                        //                      it->node=new TNode(it->pose, it->weight, it->node);
                        it->node=new TNode(it->pose, 0.0, it->node);
                        //update the weight
                }
                
                delete [] plainReading;
                aux=aux->parent;
        }
        
        //destroy the path
        aux=reversed;
        while (reversed){
                aux=reversed;
                reversed=reversed->parent;
                delete aux;
        }
}

//END State Save/Restore

//BEGIN

void  GridSlamProcessor::updateTreeWeights(bool weightsAlreadyNormalized){

  if (!weightsAlreadyNormalized) {
    normalize();
  }
  resetTree();
  propagateWeights();
}

void GridSlamProcessor::resetTree(){
  // don't calls this function directly, use updateTreeWeights(..) !

        for (ParticleVector::iterator it=m_particles.begin(); it!=m_particles.end(); it++){
                TNode* n=it->node;
                while (n){
                        n->accWeight=0;
                        n->visitCounter=0;
                        n=n->parent;
                }
        }
}

double propagateWeight(GridSlamProcessor::TNode* n, double weight){
        if (!n)
                return weight;
        double w=0;
        n->visitCounter++;
        n->accWeight+=weight;
        if (n->visitCounter==n->childs){
                w=propagateWeight(n->parent,n->accWeight);
        }
        assert(n->visitCounter<=n->childs);
        return w;
}

double GridSlamProcessor::propagateWeights(){
  // don't calls this function directly, use updateTreeWeights(..) !

        // all nodes must be resetted to zero and weights normalized

        // the accumulated weight of the root
        double lastNodeWeight=0;
        // sum of the weights in the leafs
        double aw=0;                   

        std::vector<double>::iterator w=m_weights.begin();
        for (ParticleVector::iterator it=m_particles.begin(); it!=m_particles.end(); it++){
                double weight=*w;
                aw+=weight;
                TNode * n=it->node;
                n->accWeight=weight;
                lastNodeWeight+=propagateWeight(n->parent,n->accWeight);
                w++;
        }
        
        if (fabs(aw-1.0) > 0.0001 || fabs(lastNodeWeight-1.0) > 0.0001) {
          cerr << "ERROR: ";
          cerr << "root->accWeight=" << lastNodeWeight << "    sum_leaf_weights=" << aw << endl;
          assert(0);         
        }
        return lastNodeWeight;
}

};

//END