中文说明：包含位置式PID算法、积分分离式PID，基于互功率谱的时延估计，用平面波展开法计算二维声子晶体带隙,是一种双隐层反向传播神经网络，可实现对二维数据的聚类，利用最小二乘法进行拟合多元非线性方程。
English Description：
Contains the location type, integral separating PID PID algorithm, based on cross power spectrum time delay estimation using plane-wave expansion method for calculation of band gap of two-dimensional phononic crystals, is a kind of back-propagation neural network with double hidden layer, can be realized on two dimensional data clustering, using least square fitting nonlinear equation.