清空筛选条件
清空筛选条件

Info

此问题已关闭。 请重新打开它进行编辑或回答。

Urgent: How do I perform FFT on a time signal

1 次查看（过去 30 天）
Osasu
Osasu 2013-7-26
I have a vibration time signal am working on. I am finding it difficult to write the code to perform fft on it. Could anyone help with it please? The length of the signal is 40000 while the sampling frequency is 20000.
Additionally, how are the length of the signal and sampling frequency arrived at?

此问题已关闭。

回答（3 个）

dpb
dpb 2013-7-26
doc fft
Sampling frequency is set by the hardware, time then determines the length.
Youssef Khmou
Youssef Khmou 2013-7-26
编辑：Youssef Khmou 2013-7-26
hi, given your signal X,
Fs=2e+4;
Resolution=512;
Ts=1/Fs;
N=4e+4;
T=N*Ts;
Fx=abs(fft(X,Resolution));
Frequency=(0:Resolution-1)*Fs/Resolution;
figure, plot(Frequency(1:end/2),Fx(1:end/2)); % two sided to one side
Roule
Roule 2013-7-31
编辑：Roule 2013-7-31
Hi, just use the following code:
fs=20000; % sampling frequency
N=40000; % length of signal
dF=Fs/N;
f=-Fs/2:dF:Fs/2-dF; %remember nyquist frequency?
plot(f,abs(fftshift(fft(<your signal>)/N)));
Hope this helps!

此问题已关闭。

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by