在opencv中的Kmean聚类

Question

基本上，我有两个玩家位置点，我想聚集来自Vec2f的玩家位置。

我试过的代码这个样本，但它不工作，并调用k均值功能时，它提供一个exceptin。

float *pointsdata = new float[10]; 

    for (std::map< unsigned int, Player >::iterator it = players.begin(); it != players.end(); ++it) 
    { 
     for (int i =0; i< players.size(); i++) 
     { 
      pointsdata[i] = it->second.m_Position.x; 
      pointsdata[i+1] = it->second.m_Position.y; 

     } 
    } 

    //float pointsdata[] = { 1,1, 2,2, 6,6, 5,5, 10,10}; 
    cv::Mat points(10, 2, CV_32F, *pointsdata); 
    cv::Mat labels, centers; 

    cv::kmeans(points, 3, labels, cv::TermCriteria(CV_TERMCRIT_EPS, 1000, 0), 1000, cv::KMEANS_RANDOM_CENTERS, centers); 


    cout << "labels: " << labels << endl; 
    cout << "centers " << centers << endl; 

Answer 1

您有cv :: Mat API here。你正在尝试使用的构造函数如下，对吧？

Mat (int _rows, int _cols, int _type, void *_data, size_t _step=AUTO_STEP) 
constructor for matrix headers pointing to user-allocated data 

所以，你应该做到以下几点：

if(players.size() > 10) 
{ 
    cout << "ERROR, too many players\n"; 
    // Do some error handling here 
    return; 
} 

//float pointsdata[10][2]; // use this if it doesnt need to be dynamic 
/* 2D definition, but we need to create it as a 1D array with room for the 2d 
float **pointsdata = new float*[10]; 
for(int i = 0; i < 10; ++i) 
{ 
    pointsdata[i] = new float[2]; 
} 
*/ 
float *pointsdata = new float[10*2]; 

for (std::map< unsigned int, Player >::iterator it = players.begin(); 
    it != players.end(); 
    ++it) 
{ 
    for (int i =0; i< players.size() && i < 10; i++) 
    { 
     pointsdata[i] = it->second.m_Position.x; 
     pointsdata[i + 10*i] = it->second.m_Position.y; 
    } 
} 

cv::Mat points(10, 2, CV_32F, pointsdata);