中文说明：基于kaiser窗的双谱线插值FFT谐波分析，对于初学者具有参考意义，一个计算声子晶体结构的一维传递矩阵法,包括四元数的各种计算,代码里有很完整的注释和解释，信号处理中的旋转不变子空间法。
English Description：
Based on the Kaiser window double spectrum line interpolation FFT harmonic analysis, for beginners has reference significance, a computing one-dimensional phononic crystal structure of transfer matrix method, including quaternion calculation, the code is very complete annotated and explained, signal processing in the rotation invariant subspace method.