c++ - OpenCV memory error occurs while tring to calculate the sum of 2 matrices -

i found code , try compile it, not work. error brought @ line:

q_matrix_tilde += q_tilde * q_tilde_transposed; 

it told me there error related memory, not understand why. me?

   // alessandro gentilini  #include <cv.h> #include <cxcore.h> #include <vector> using namespace std; using namespace cv;  // estimation of affine 2d transformation means of least squares method. // reference: // spÄth, helmuth. fitting affine , orthogonal transformations between 2 sets of points. mathematical communications, 2004, 9.1: 27-34. // http://hrcak.srce.hr/file/1425  template < typename point2d_t, typename point3d_t > class leastsquare2daffinetransformationestimator { public:    // solves linear systems descripted formula (17)    static cv::mat estimate( const std::vector<point2d_t>& p, const std::vector<point2d_t>& q )    {       mat q_tilde = q_set_to_q_matrix_tilde(p);        mat c_tilde_0 = c_j_tilde(0,p,q);       mat c_tilde_1 = c_j_tilde(1,p,q);        mat q_tilde_inv = q_tilde.inv();       mat a_tilde_0 = q_tilde_inv * c_tilde_0;       mat a_tilde_1 = q_tilde_inv * c_tilde_1;        cv::mat t = cv::mat::zeros( 3, 2, cv::datatype<point2d_t::value_type>::type );       cv::mat(a_tilde_0).copyto(t.col(0));       cv::mat(a_tilde_1).copyto(t.col(1));       cv::transpose(t,t);       return t;    }  private:    // implements formula (12)    static cv::mat q_to_q_tilde( const point2d_t& q )    {        vector<point2d_t> v;        v.push_back(point2d_t(q.x));        v.push_back(point2d_t(q.y));        v.push_back(point2d_t(1));       return cv::mat(v,true);    }     // implements formula (14)    static cv::mat q_set_to_q_matrix_tilde( const std::vector<point2d_t>& q_set )    {       size_t m = q_set.size();        cv::mat q_matrix_tilde = cv::mat::zeros( 3, 3, cv::datatype<point2d_t::value_type>::type );       cv::mat temp= cv::mat::zeros( 3, 3, cv::datatype<point2d_t::value_type>::type );       cv::mat temp1= cv::mat::zeros( 3, 3, cv::datatype<point2d_t::value_type>::type );       cv::mat q_tilde = cv::mat::zeros( 3, 1, cv::datatype<point2d_t::value_type>::type );       cv::mat q_tilde_transposed = cv::mat::zeros( 1, 3, cv::datatype<point2d_t::value_type>::type );       ( size_t = 0; < m; i++ ) {          q_tilde = q_to_q_tilde(q_set[i]);          cv::transpose( q_tilde, q_tilde_transposed );          /*cout<<q_tilde_transposed.col<<" "<<q_tilde_transposed.row<<endl;*/          temp = q_tilde * q_tilde_transposed;          cv::add(temp,q_matrix_tilde,temp1);       }       return q_matrix_tilde;    }     // implements formula (16)    static cv::mat c_j_tilde( const size_t& j, const std::vector<point2d_t>& q_set, const std::vector<point2d_t>& p_set )    {       if ( q_set.size() != p_set.size() ) {          throw 0;       }        if ( j > 2 ) {          throw 1;       }        size_t m = q_set.size();        point2d_t::value_type p_ji;        point2d_t::value_type c_j0 = 0;       ( size_t = 0; < m; i++ ) {          switch( j ) {          case 0: p_ji = p_set[i].x; break;          case 1: p_ji = p_set[i].y; break;          }          c_j0 += q_set[i].x * p_ji;       }        point2d_t::value_type c_j1 = 0;       ( size_t = 0; < m; i++ ) {          switch( j ) {          case 0: p_ji = p_set[i].x; break;          case 1: p_ji = p_set[i].y; break;          }          c_j1 += q_set[i].y * p_ji;       }        point2d_t::value_type c_j2 = 0;       ( size_t = 0; < m; i++ ) {          switch( j ) {          case 0: p_ji = p_set[i].x; break;          case 1: p_ji = p_set[i].y; break;          }          c_j2 += 1 * p_ji;       }       vector<point2d_t> v;       v.push_back(point2d_t(c_j0));       v.push_back(point2d_t(c_j1));       v.push_back(point2d_t(c_j2));       cv::mat vv = mat(v,true);       return vv;    }   };  #include <vector> #include <iostream>  int main( int argc, char** argv ) {    std::vector<cv::point2f> p,q;     p.push_back(cv::point2f( 1, 0));    p.push_back(cv::point2f( 0, 1));    p.push_back(cv::point2f(-1, 0));    p.push_back(cv::point2f( 0,-1));     q.push_back(cv::point2f(1+sqrtf(2)/2, 1+sqrtf(2)/2));    q.push_back(cv::point2f(1-sqrtf(2)/2, 1+sqrtf(2)/2));    q.push_back(cv::point2f(1-sqrtf(2)/2, 1-sqrtf(2)/2));    q.push_back(cv::point2f(1+sqrtf(2)/2, 1-sqrtf(2)/2));     //std::cout <<    leastsquare2daffinetransformationestimator<cv::point2f,cv::point3f>::estimate(p,q);     return 0; } 

your code works perfect. have run , result:

[0.70710683, -0.70710683 1,  0.70710683,  0.70710683 1]