说明：  本帖调用自编函数（grating）绘制光栅条纹图像，通过例子讲解水平、竖直、环状和辐射状光栅条纹图像的绘制，用黑白和彩色显示效果给大家视觉上的震撼。调用自编函数时，可以通过成对出现的参数控制条纹的方向、颜色、周期、相位角等。
(This post calls self-function (grating) draw grating image, by way of example to explain the horizontal, vertical, circular and radial grating image rendering, with monochrome and color display give you visual shock. Self function call, the parameters can be controlled by pairs stripe orientation, color, period, phase angle.)