ECG, FFT and IFFT

el_supremo:
Why do you "need to perform" the IFFT? What is it going to tell you?

To compare with my FFT input.

el_supremo:
To add to what @jremington has just posted, the result of an IFFT won't necessarily produce exactly the same data as your input to the FFT, so it's not a good test of an FFT library.

I thought IFFT would result the same data as input to the FFT, haha. Sorry, I'm just a beginner.

My teacher told me to verify that, but, well... ok.

He told me like "Do FFT and then IFFT to make sure FFT is working well".

Look, I need to apply filters (low pass/high pass/band pass/band stop) in the ECG signals to clear it.

How can I do that? Can you guys help me? I really would like to learn.