采用蒙特卡罗方法模拟固态相变的晶粒长大过程，可以设置3D网格大小，蒙特卡罗步等参数，适用于模拟金属再结晶过程。(The simulation model of process in grain growth is provided by this code in matlab. The parameters of mote carlo method can be inputted by the users according to their own usage.)