nearest_neighbor_classifier.cpp

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#include "ml_classifiers/nearest_neighbor_classifier.h"
#include <pluginlib/class_list_macros.h>

PLUGINLIB_DECLARE_CLASS(ml_classifiers, NearestNeighborClassifier, ml_classifiers::NearestNeighborClassifier, ml_classifiers::Classifier)

using namespace std;

namespace ml_classifiers{

    NearestNeighborClassifier::NearestNeighborClassifier(){}
    
    NearestNeighborClassifier::~NearestNeighborClassifier(){}
    
    void NearestNeighborClassifier::save(const std::string filename){}
    
    bool NearestNeighborClassifier::load(const std::string filename){return false;}
    
    void NearestNeighborClassifier::addTrainingPoint(string target_class, const std::vector<double> point)
    {
        class_data[target_class].push_back(point);
    }
    
    void NearestNeighborClassifier::train(){}
    
    void NearestNeighborClassifier::clear()
    {
        class_data.clear();
    }
    
    string NearestNeighborClassifier::classifyPoint(const std::vector<double> point)
    {
        size_t dims = point.size();
        double min_diff=0;
        string ans;
        bool first = true;
        
        for(ClassMap::iterator iter = class_data.begin(); iter != class_data.end(); iter++){
            string cname = iter->first;
            CPointList cpl = iter->second;
            
            for(size_t i=0; i<cpl.size(); i++){
                double diff = 0;
                for(size_t j=0; j<dims; j++){
                    diff += fabs(cpl[i][j] - point[j]);
                }
                if(first){
                    first = false;
                    min_diff = diff;
                    ans = cname;
                }
                else if(diff < min_diff){
                    min_diff = diff;
                    ans = cname;
                }
            }
        }
        return ans;
    }

}