Why are low frequency peaks not sharp in scipy fft?

1. Why does FFT have two peaks?
2. What do peaks in FFT represent?
3. How do you find the frequency of data using FFT?

Why does FFT have two peaks?

It's not two peaks, it's one peak, but an FFT is always mirror-symmetric. Only the first half is actually useful. Think of it this way: an FFT can't pick up signal data at more than half the sampling rate. When you try you get essentially garbage data that just so happens to be a mirrored refection of the "real" FFT.

What do peaks in FFT represent?

FFTs of complex vibrations have multiple peaks- one for each frequency present in the vibration. Low frequency peaks are shown at the left end of the graph. The left-most peak represents the fundamental. Other peaks indicate overtones.

How do you find the frequency of data using FFT?

Let X = fft(x) . Both x and X have length N . Suppose X has two peaks at n0 and N-n0 . Then the sinusoid frequency is f0 = fs*n0/N Hertz.