Problem about SVM example in OpenCV3.0.0 [closed]

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In http://docs.opencv.org/3.0.0/d1/d73/tutorial_introduction_to_svm.html there exists an example of SVM.

The expected result image is:

There are gray circle around three support vectors.

But after implement the example, the image I got is:

There is no gray circle around any support vector. Only a quater of gray circle appeared at top left corner.

What is the problem ?

My environment is as follows: Windows 10, Visual Studio 2013, opencv-3.0.0。