how to know the frequency on the fft plot
23 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
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 Kommentare
Antworten (1)
Walter Roberson
am 31 Jul. 2015
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 Kommentare
Siehe auch
Kategorien
Mehr zu Transforms finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!