How to smooth signal and find dominant freqeuncy using FFT?

Hi. I am not so familiar with signal processing. I have this oscillation which I like to find its dominant frequency. I used FFT, but it does not give me any specific value.

After all, can we define any frequency for this kind of oscillations? How can I smooth the data? I used filter and sgolayfilt, but they didn;t change the data at all.

Thanks in advance!

Steven

Answer 1

[Samudrala Jagadish]

If you want to smooth the given signal without using FFT Filtering, they you may use a concept called "Moving Average Filter" Please follow my file exchange link as given below it contains a code to smooth a signal upto some extent

here is the link:

http://in.mathworks.com/matlabcentral/fileexchange/53241-signal-smoothing-or-moving-average-filter