How can i get main wave from frequency data?

I want to get: 1-get frequency of wave or signal whit fft. 2- create sin waves and sum them from frequency data, to create wave like main wave;

this is my code but its not work.

[Image Analyst]

We can't run an image and no one is going to type all that in.

In general you can take the fft to see the power at different frequencies. You can look for spikes for particularly strong frequencies. So identify the peak. You can then zero out everything else and inverse transform. Or just take the known frequency of the peak and reconstruct a perfect, noise free signal knowing that frequency.

If you have any more questions, then attach your data and code to read it in ("tst'm") with the paperclip icon after you read this:

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