实验数据的傅里叶变换
我尝试在 Matlab 中对从风洞实验中获取的一些数据进行快速傅里叶变换，试图显示流动中速度变化的频率，但不知何故，我一直将 0Hz 作为主频率。任何人以前遇到过这个问题并且知道如何解决它或者可以更好地向我解释如何进行频率变换。
Ps：似乎可以正常进行快速傅里叶变换，问题可能出在将数据从虚数转换为实值时，
请帮助我！
谢谢你！
I've tried to do a fast fourier transform in Matlab of some data taken from an experiment in the windtunnel trying to show the frequency of the velocity variation in a flow, but somehow I keep on getting 0Hz as the main frequency. Anyone has encountered this problem before and knows how to solve it or can explain me a bit better how to do the frequency transform.
Ps: It seems to be doing the fast fourier transform alright, the problem might be when converting the data from imaginary to real values
Help me please!
Thank you!
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（1）
遇到这种情况是很正常的事情。 0 Hz 分量（通常称为DC 分量，与电气等效物类似）是数据的恒定、非时变部分——它相当于数据的平均值。如果您的数据均值不为零，这是很正常的事情。
如果您愿意，您可以计算平均值，然后从数据系列中减去它，但这并不是真正必要的，因为它只会改变 FFT 的 DC 分量。如果您对直流分量不感兴趣，则可以忽略它。
This is a pretty normal thing to encounter. The 0 Hz component (often referred to as the DC component in analogy to the electrical equivalent) is the constant, non-time-varying component of the data -- it's equivalent to the mean of the data. If you have data that does not have a mean of zero, this is a very normal thing to see.
If you want to, you can calculate the mean and then subtract it from your data series, but this is not really necessary, since it will only change that DC component of the FFT. If you're not interested in the DC component for your purposes, you can simply ignore it.