该程序用来读取图片上某个点的坐标

利用鼠标取4个点，依次是坐标原点，X轴上的第一个刻度点，y轴上的第一个刻度点，需要读取数据点，则可以获得该数据点的坐标。-　Of the program used to read the coordinates of a point on the picture　use of the mouse to take four points, followed by a scale point of the origin of coordinates, the X-axis, y-axis scale, you need to read data points, you can get the coordinates of the data points.