to show the waveform of audio file and play it on computer Purpose: Familiar with WAV file format and UI design It should have the following functions: Provide a Graphic User Interface for user to browse the file system and select one WAV file

1．找点一段心电信号，画出信号时域波形和频谱图； 2. 利用MATLAB中的随机函数产生噪声加入到心电信号中，使心电信号被污染，读出污染后的号并画出对应信号的时域波形和频谱图； 3．用双线性变换法设计一个Butterworth带通滤波器，输出所设计的滤波器的阶次，分子、分母多项式的系数，画出滤波器的频率响应（幅频响应和相频响应）曲线；（也可以根据自己需要设置滤波器性能指标） 带通通滤波器设计性能指标：fs1=10Hz, fp1=20Hz, fp1=1000Hz, fs2=120

用于心电的一种低通数字滤波算法，该方法设计简单、运算量小，对有用信号的影响小。同时设计了相关的界面，用于实时显示心电信号的波形，且可以在不同背景下将心电信号显示出来。-Used for the ECG a low pass digital filtering algorithm, the method is designed to be simple, small amount of computation, the impact of the useful signal. While the

单相并网逆变器并网电流中含有大量谐波，传统的PI 控制器难以满足波形跟踪需要，此处采用比例+复的复合控制算法用于逆变器电流环控制器设计(The single-phase grid-connected inverter has a large amount of harmonics in the grid-connected current. The traditional PI controller can not meet the needs of waveform tracking. Her