title: what is Vec4i in opencv
body: <p>i am learning opencv using c++. i came across Vector in a code for hough line transform . can anyone explain me what does Vec4i store and what does 4i mean.
  the code snippet:-</p>
  
  <pre><code>vector&lt;Vec4i&gt; lines;
    HoughLinesP(dst, lines, 1, CV_PI/180, 50, 50, 10 );
    for( size_t i = 0; i &lt; lines.size(); i++ )
    {
      Vec4i l = lines[i];
      line( cdst, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0,0,255), 3, CV_AA);
    }
  </code></pre>