一种用于生成二维数据分布图形的函数,在观察大数据量的数据集合是很有效.-A function to plot the distribution of 2-dimensional data

经典二维物理引擎，box2d，大家可自行参考-Classical two-dimensional physics engine, box2d, we can self-refer

使用二维表来实现状态机，该状态机用在通信协议中，基于TCP协议-Using two-dimensional table to implement a state machine, the state machine is used in communication protocols based on TCP protocol