AveragePrecision.cpp

#include "AveragePrecision.h"
#include "macroses.h"

namespace DirectGraphicalModels 
{
    float getAveragePrecision(const vec_byte_t &predictions, const vec_float_t &potentials, const vec_byte_t &gt, byte state)
    {
        // Assertions
        DGM_ASSERT(predictions.size() == potentials.size());
        DGM_ASSERT(predictions.size() == gt.size());
        
        std::vector<std::tuple<byte, float, byte>> container;           // < prediction | pot | gt >
        for (size_t i = 0; i < predictions.size(); i++)
            container.push_back(std::make_tuple(predictions[i], potentials[i], gt[i]));
        // Sorting on potentials
        std::sort(container.begin(), container.end(), [](auto const &left, auto const &right) { return std::get<1>(left) > std::get<1>(right); });
    
        float   res             = 0.0f;
        int     nRelevants      = 0;                    // number of relevant elements
        int     nCoincidences   = 0;                    // number of correct predictions
        int     i               = 0;
        for (auto &c : container) {
            i++;
            if (std::get<2>(c) == state) {              // if (gt == state)
                nRelevants++;
                if (std::get<0>(c) == state) {          // if (prediction = state)
                    nCoincidences++;
                    res += static_cast<float>(nCoincidences) / i;
                }
            }
        }
        
        DGM_IF_WARNING(nRelevants == 0, "There are no states <state> in <gt>");

        if (nRelevants > 0) res /= nRelevants;

        return res;
    }

}