Method kmeans

deps/opencv/modules/core/src/matrix.cpp:2698–2937

}

double cv::kmeans( InputArray _data, int K,
                   InputOutputArray _bestLabels,
                   TermCriteria criteria, int attempts,
                   int flags, OutputArray _centers )
{
    const int SPP_TRIALS = 3;
    Mat data0 = _data.getMat();
    bool isrow = data0.rows == 1 && data0.channels() > 1;
    int N = !isrow ? data0.rows : data0.cols;
    int dims = (!isrow ? data0.cols : 1)*data0.channels();
    int type = data0.depth();

    attempts = std::max(attempts, 1);
    CV_Assert( data0.dims <= 2 && type == CV_32F && K > 0 );
    CV_Assert( N >= K );

    Mat data(N, dims, CV_32F, data0.data, isrow ? dims * sizeof(float) : static_cast<size_t>(data0.step));

    _bestLabels.create(N, 1, CV_32S, -1, true);

    Mat _labels, best_labels = _bestLabels.getMat();
    if( flags & CV_KMEANS_USE_INITIAL_LABELS )
    {
        CV_Assert( (best_labels.cols == 1 || best_labels.rows == 1) &&
                  best_labels.cols*best_labels.rows == N &&
                  best_labels.type() == CV_32S &&
                  best_labels.isContinuous());
        best_labels.copyTo(_labels);
    }
    else
    {
        if( !((best_labels.cols == 1 || best_labels.rows == 1) &&
             best_labels.cols*best_labels.rows == N &&
            best_labels.type() == CV_32S &&
            best_labels.isContinuous()))
            best_labels.create(N, 1, CV_32S);
        _labels.create(best_labels.size(), best_labels.type());
    }
    int* labels = _labels.ptr<int>();

    Mat centers(K, dims, type), old_centers(K, dims, type), temp(1, dims, type);
    vector<int> counters(K);
    vector<Vec2f> _box(dims);
    Vec2f* box = &_box[0];
    double best_compactness = DBL_MAX, compactness = 0;
    RNG& rng = theRNG();
    int a, iter, i, j, k;

    if( criteria.type & TermCriteria::EPS )
        criteria.epsilon = std::max(criteria.epsilon, 0.);
    else
        criteria.epsilon = FLT_EPSILON;
    criteria.epsilon *= criteria.epsilon;

    if( criteria.type & TermCriteria::COUNT )
        criteria.maxCount = std::min(std::max(criteria.maxCount, 2), 100);
    else
        criteria.maxCount = 100;