中文说明：
仿照着《小波去噪中软硬阈值的一种改良折衷法》一文写的程序，对比了软、硬以及软硬阈值折衷法的信噪比及均方根误差。仿真出来之后，原信号的信噪比是负的，不知道为什么？均方根误差的值也比较大，不知何解？信噪比和均方根误差是参照《基于matlab的小波去噪仿真》：吴伟，《信息与电子工程》 一文写的
English Description：
This paper compares the signal-to-noise ratio (SNR) and root mean square error (RMS) of soft, hard and soft hard thresholding compromise methods by imitating the program written in "an improved compromise method of soft and hard thresholding in wavelet denoising". After the simulation, the signal-to-noise ratio of the original signal is negative, I don't know why? The value of root mean square error is also relatively large? Signal to noise ratio and root mean square error refer to the article "wavelet denoising simulation based on MATLAB": Wu Wei, information and electronic engineering