how to use the output of Sub-Pixel Edge Detection Algorithm

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Hi, I am using Sub-Pixel Edge Detection algorithm Implementing according to Carsten Steger's method. The Algorithm is taken from Github :https://github.com/songyuncen/EdgesSubPix

The output is a struct as following

struct Contour
{
    std::vector<cv::Point2f> points;  // edge location
    std::vector<float> direction;     // direction of the gradient in edge point, 
                                      // starting from y axis, counter-clockwise
    std::vector<float> response;      // amptitude of the gradient in edge point
};

How do i use the data of direction and response parameters for drawing and what is the meaning of these parameters?

Thanks