title: What is the structure of Point2f in openCV?
body: <p>I am confused about what does <code>Point2f</code> returns. I have <code>vector&lt;Point2f&gt; corner;</code> So, what would be the coordinate of rows and columns? Will  it be following:</p>
  
  <pre><code>int row_coordinate = corner[i].x;
  int col_coordinate = corner[i].y;
  </code></pre>
  
  <p>But I get a segmentation fault if I take the above-mentioned convention. And if I do it like </p>
  
  <pre><code>int row_coordinate = corner[i].y;
  int col_coordinate = corner[i].x;
  </code></pre>
  
  <p>then I get the results but then it seems to be opposite to the OpenCV documentation. Kindly tell me which one is correct. Would be very nice if you provide some documentation link (which I have already tried to search a lot).</p>