最近看到有人提问怎样用FFT实现频谱分析，我认为能够进行到频谱分析的人，对于系统研究的深度基本上已经相当不错了。本人今天做了一个例程，发给大家参考一下。

历程主要内容(signal_analyzer.rar)如下：

test1.txt 第一列为时间t，0.001s为步长；第二列为系统的输入信号；第三列为系统的输出信号。

signal_analyzer.m首先将test1.txt 的数据读入workspace，然后进行FFT，分析出两信号的频率，输出对于输入的幅值衰减（db），输出对输入的相位差。-The question was asked recently to see the realization of how to use FFT spectral analysis, I think that spectral analysis can be carried out to those who study the depth of the system basically is already quite good. Today I made a routine, distributed to Members for reference. The main contents of the course (signal_analyzer.rar) are as follows: test1.txt the first time as t, 0.001s for the step　the second as the system input signal　the third as a system output signal. signal_analyzer.m first test1.txt data read into workspace, and then proceed to FFT, analysis of the two signal frequency, output amplitude for input attenuation (db), the output of the input phase difference.相关搜索： 相位差
db
frequency
signal
analyzer
幅值
信号
频谱
分析