▍1. thresholdHSI
采用小波变换的方法实现心电信号的滤波,分别使用了硬阈值、软阈值和改进阈值方法,并实现了滤波效果的评价(均方差和信噪比)(Wavelet transform of ECG signal filtering method, respectively, using a hard threshold and soft threshold and improve the threshold method, and to achieve the filtering effect of the evaluation (both variance and signal to noise ratio))