中文说明： 用平面波展开法计算二维声子晶体带隙,多姿态，多角度，有不同光照,基于欧几里得距离的聚类分析，是国外的成品模型，关于超声波倒车雷达测距的，用蒙特卡洛模拟的方法计算美式期权的价格以及基本描述。
English Description：
Using the plane wave expansion method for calculation of band gap of two-dimensional phononic crystals, pose, angle, light, cluster analysis based on Euclidean distance, is the product of foreign models, ultrasonic parking sensor range, using Monte Carlo simulation method to calculate the price of American options and basic descriptions.