ClusteringComparison.cc

#include <cassert>
#include "ClusteringComparison.h"

namespace stab {
    double TransversePairwiseIndex::index(const PseudoJet* inputParticles,
                                          const unsigned* clustering1,
                                          const unsigned* clustering2,
                                          const unsigned len) const
    {
        assert(inputParticles);
        assert(clustering1);
        assert(clustering2);
        assert(len);

        long double c1 = 0.0L, c2 = 0.0L, c3 = 0.0L, c4 = 0.0L;

        for (unsigned i=1; i<len; ++i)
        {
            const double pt_i = inputParticles[i].pt();
            const unsigned cl_i_1 = clustering1[i];
            const unsigned cl_i_2 = clustering2[i];

            for (unsigned j=0; j<i; ++j)
            {
                const double weight = inputParticles[j].pt()*pt_i;
                const bool same_in_1 = (cl_i_1 == clustering1[j]);
                const bool same_in_2 = (cl_i_2 == clustering2[j]);

                if (same_in_1 && same_in_2)
                    c1 += weight;
                else if (same_in_1 && !same_in_2)
                    c3 += weight;
                else if (!same_in_1 && same_in_2)
                    c4 += weight;
                else
                    c2 += weight;
            }
        }

        assert(c1 + c2 + c3 + c4 > 0.0L);
        return combineCounts(c1, c2, c3, c4);
    }
}