此程序为gui的一个演示程序，展示给朋友们一个lissa曲线-This is a demonstrate programe of gui,it is show our friend a lissa curve.

可要求绘制正弦信号，余弦信号等，并可改变信号在图中的显示区域，同时可选择是否加格-this programe could draw different kinds of signal such as sin and cos signals ,and changes the show areas of the signal.This progame could also add the grid on the screen.