说明：  该程序模拟了在圆形平台上通过衍射光栅的干涉。视点设置在以光栅中心为中心的圆周上，因此唯一的变化是视角，而不是与光栅中心的距离。
(This program simulates the pehonemenon of interference via a diffraction grating on a circular platform. The view point is set on a circumference centered in the center of the grating, so the only change is the view angle, but not the distance from the center of the grating.)