此函数用于研究Mallet算法及滤波器设计

此函数用于消噪处理

分解的高频系数采用db9较好,即它的消失矩较大

分解的有用信号小波高频系数基本趋于零

对于噪声信号高频分解系数很大，便于阈值消噪处理-this function for research Mallet filter algorithm design and function for Denoising decomposition of high-frequency coefficients Terminal better that it's vanishing moments larger decomposition of useful signal, high-frequency coefficients tends to zero for high-frequency signal noise decomposition coefficient great ease threshold Denoising