FINDING FREQUENCY AND AMPLITUDE OF A SINUSOID FROM DATA POINTS.

128 views (last 30 days)
Hello,
I have a text file with two columns: One with the time instant and the other with the corresponding velocity of a sound wave at a particular point at that instant. I know that the wave is a sinusoid (After plotting).
How can I find the exact frequency and amplitude of the wave? Is there a function in MATLAB?
Thanks in advance.

Answers (1)

rifat
rifat on 27 May 2014
len=length(signal);
fs=50 % assuming you know the sampling frequency of your signal
n=0:len-1;
N=n*fs/(len-1); % convert x-axis in actual frequency
y=fft(signal);
plot(N,abs(y));
from the plot you can determine the frequency peak. I do not know any function for amplitude estimation. If the signal relatively low noisy, then (max(signal)-min(signal))/2 should give a rough estimate
  2 Comments

Sign in to comment.

Community Treasure Hunt

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

Start Hunting!