how to know the frequency on the fft plot
9 ビュー (過去 30 日間)
古いコメントを表示
if I'm doing fft of my signal, and ploting it
plot(abs(fft(x)).
Now how do I match an index on the graph to a specific frequency? I came to the formula of -
f = (FPS/N)*(i-1)
f - the frequency I am looking for
FPS - the Frames Per Second of the original signal in the time domain
N - total number to recorded frames in the time domain
i - index on x-axis on my abs(fft(x)) plot.
does that correct?
0 件のコメント
回答 (1 件)
Walter Roberson
2015 年 7 月 31 日
Yes, except that it only works for the first half of the fft.
See http://www.mathworks.com/help/matlab/ref/fft.html and notice how they only plot the first half with a formula for "f" that works out the same as the one you have.
0 件のコメント
参考
カテゴリ
Help Center および File Exchange で Fourier Analysis and Filtering についてさらに検索
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!