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Magnitude of FFT

Hi,

I create from a curve a FFT. The amplitude of the curve is of 1, but the magnitude of the FFT is a lot lot time higher than the original data. I have observed that it changes according to the number of point data from the original curve. Is a procedure to fix this? or I am missinterpreting something?

Thanks

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Altair Forum User

Hi @Francisco
Can you divide the fft’s y by (N/2) where N is the number of samples and check the results?

Altair Forum User

Hi @Prakash Pagadala

Dividing by (N/2) seems ok. I was making some tests, I plotted a sine wave with amplitude of 1, calculated the FFT and extracted the magnitude. I did this for different sampling numbers. After dividing the amplitude by (N/2) i got results closer to 1.00. But not always, must of the times it was less than 1.00. I understand that this might be because of leakage, and this might be corrected windowing the signal, is this assumption correct?