[OpenCV] 2D point to vector form

void lsd_vector_form(std::vector<std::vector<float>> &L, std::vector<std::vector<float> > &L_vec, uint no_of_lines)
{
    L_vec.resize(3); //Height
    for (int i = 0; i < 3; ++i)
    {
        L_vec[i].resize(no_of_lines);
    }
    cv::Mat A(3, 3, CV_32F);
    cv::Mat s, u, vt;
    A.at<float>(0, 2) = 1;
    A.at<float>(1, 2) = 1;
    A.at<float>(2, 0) = 0;
    A.at<float>(2, 1) = 0;
    A.at<float>(2, 2) = 0;
    for (int i = 0; i < no_of_lines; ++i)
    {
        A.at<float>(0, 0) = L[0][i];
        A.at<float>(0, 1) = L[1][i];
        A.at<float>(1, 0) = L[2][i];
        A.at<float>(1, 1) = L[3][i];
        cv::SVD::compute(A, s, u, vt);  //YY=U*S*V'
        vt = vt.t();
        vt.col(0) = vt.col(0)*-1;
        L_vec[0][i] = vt.at<float>(0, 2);
        L_vec[1][i] = vt.at<float>(1, 2);
        L_vec[2][i] = vt.at<float>(2, 2);
    }
}