matlab fft多周期各采样点在电力电子上的谐波分析，采样频率2000，总采样点数1320，通过输入数据文档txt文件名，实现绘图及THD分析-matlab fft multi-cycle of each sampling point on the harmonic analysis in power electronics, the sampling frequency of 2000, the total number of samples 1320, the txt file name of the input data files, graphics and THD analysis