Periodicity using Fourier transform
显示 更早的评论
Hi everyone, I have a simple question concerning how to find the periodicity of an oscillating function using the Fourier transform. Let's suppose to have an oscillating function y=f(x) where x and y are two vectors and x is the time vector expressed in second (s). Can you suggest me a code to retrieve the frequency (or frequencies) of this function, expressed in herz (i.e. 1/s) by using the Fourier transform? Thanks a lot.
回答（1 个）
Walter Roberson
2016-11-18
0 个投票
If the times are uniform intervals then do peak finding on fft(y-mean(y))
See the fft example for how to calculate the frequency from bin and fs and length
2 个评论
aurc89
2016-11-18
Walter Roberson
2016-11-18
For x at equal time intervals,
L = length(y);
Fs = 1/(x(2)-x(1));
f = Fs*(0:(L/2))/L;
Now the first length(f) positions in fft(y-mean(y)) are associated with corresponding frequencies in f, so if you find a peak at position K then the frequency corresponding is f(K)
类别
在 帮助中心 和 File Exchange 中查找有关 Fourier Analysis and Filtering 的更多信息
2016-11-18
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
