基于互功率谱的时延估计，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,计算晶粒的生长，入门级别程序。- Based on the time delay estimation of power spectrum, Monte Carlo simulation method of calculating the American option price and basic descr iption, Calculation of growth, entry-level program gra