对信号进行频谱分析时，数据样本应有足够的长度，一般FFT程序中所用数据点数与原含有信号数据点数相同，这样的频谱图具有较高的质量，可减小因补零或截断而产生的影响。-The signal spectrum analysis, data sample should be of sufficient length, the general FFT program used in the data points with the same number of data containing the signal spectrum, that has high quality, can decrease the influence caused by zero padding or truncation.