实现以下功能：装载信号；完成信号的单尺度一维离散小波分解；从系数中重构低频部分和高频部分；显示高频和低频部分；由小波逆变换恢复信号；多层一维分解；提取系数的低频和高频部分；重构第3层的低频系数；重构第1、2、3、4、5层的高频信号；重构原始信号并显示-Achieve the following functions: load signal　complete signal single-scale one-dimensional discrete wavelet decomposition　reconstructed from the coefficients in the low frequency and high frequency　display high-frequency and low frequency　restored by the inverse wavelet transform signal　multi-layer one-dimensional decomposition　extraction coefficient of low frequency and high frequency　reconstruction of 3-layer low-frequency coefficients　reconstruction of the first layer of high-frequency signal 1,2,3,4,5　reconstruct the original signal and display