How do I find the oscillation of these wobbles on matlab?

Answer 1

[Star Strider]

I am not certain what you want.

If you want to find the predominant frequency, the best way is likely to use the fft function.

If you want to find the individual peak and trough locations, first use the detrend function to remove the linear trend, then findpeaks on the original vector to locate the peaks and the negative of the vector to locate the troughs. The islocalmax and islocalmin functions can also be used to find the peaks and troughs, respectively.

[Hamza Aboumaray]

How would the code look like for calculating the oscillation of the graph?

[Star Strider]

It depends on what you mean by ‘calculating the oscillation’. What result do you want?

I have no idea what you want to do with the data you plotted.

[Hamza Aboumaray]

In my assignment it says to calculate the oscillation of the wobbles in the plot.

[Star Strider]

That gives me no useful information. I have no idea what that means.

Taking a guess, I would use the fft function (that I already linked to). That will give you the frequencies in the vector. (It would not be necessary to detrend the vector first to use fft, however it would be advisable to detrend it.)

The documentation on the fft function (and detrend that I also already linked to, if you choose to use it) will provide you with the code necessary to use the functions with your vector.

[Hamza Aboumaray]

It's fine I agree with you the question is not very clear in the assignment. Thanks for your help anyway!

[Image Analyst]

What did your textbook or instructor talk about recently? I bet you're supposed to use whatever method they discussed.

[Star Strider]

Hamza Aboumaray — My pleasure!