How are two-element vector represented in a OpenCV Mat in Java?

Question

I was looking at Opencv Java documentation of Hough Transform.

The return value lines is in a Mat data type described as:

Answer 1

Here's some code I used a while ago, in version 2.4.8 I think. matLines came from this:

Imgproc.HoughLinesP(matOutline, matLines, 1, Math.PI / 180, houghThreshCurrent, houghMinLength, houghMaxGap);

...

Point[] points = new Point[]{ new Point(), new Point() };
for (int x = 0; x < matLines.cols(); x++) {
   double[] vec = matLines.get(0, x);
   points[0].x = vec[0];
   points[0].y = vec[1];
   points[1].x = vec[2];
   points[1].y = vec[3];
   //...
}