C++ (Cpp) update_medians示例

示例#1

文件： kmedians.cpp 项目： annoviko/pyclustering

void kmedians::process(const dataset & data, cluster_data & output_result) {
    m_ptr_data = &data;
    m_ptr_result = (kmedians_data *) &output_result;

    if (data[0].size() != m_initial_medians[0].size()) {
        throw std::invalid_argument("kmedians: dimension of the input data and dimension of the initial medians must be equal.");
    }

    m_ptr_result->medians() = m_initial_medians;

    double changes = std::numeric_limits<double>::max();
    double prev_changes = 0.0;

    std::size_t counter_repeaters = 0;

    for (std::size_t iteration = 0; (iteration < m_max_iter) && (changes > m_tolerance) && (counter_repeaters < 10); iteration++)
    {
        update_clusters(m_ptr_result->medians(), m_ptr_result->clusters());
        changes = update_medians(m_ptr_result->clusters(), m_ptr_result->medians());

        double change_difference = std::abs(changes - prev_changes);
        if (change_difference < THRESHOLD_CHANGE) {
            counter_repeaters++;
        }
        else {
            counter_repeaters = 0;
        }

        prev_changes = changes;
    }

    m_ptr_data = nullptr;
    m_ptr_result = nullptr;
}

示例#2

文件： kmedians.cpp 项目： Gudui/pyclustering

void kmedians::process(const std::vector<point> & data) {
    m_ptr_data = (std::vector<point> *) &data;
    if (data[0].size() != m_medians[0].size()) {
        throw std::runtime_error("CCORE [kmedians]: dimension of the input data and dimension of the initial cluster medians must be equal.");
    }

    m_clusters.clear();

    double stop_condition = m_tolerance * m_tolerance;
    double changes = 0.0;
    double prev_changes = 0.0;

    size_t counter_repeaters = 0;

    do {
        update_clusters();
        changes = update_medians();

        double change_difference = abs(changes - prev_changes);
        if (change_difference < 0.000001) {
            counter_repeaters++;
        }
        else {
            counter_repeaters = 0;
        }

        prev_changes = changes;
    }
    while ((changes > stop_condition) && (counter_repeaters < 10));

    m_ptr_data = nullptr;
}