What is the general formula for stacked DFT on the same signal?

1. What happens if we apply DFT twice to a signal?
2. How is DFT calculated?
3. How do you calculate DFT frequency?
4. How is DFT calculated in FFT?

What happens if we apply DFT twice to a signal?

Applying the DFT twice results in a scaled, time reversed version of the original series. The transform of a constant function is a DC value only.

How is DFT calculated?

The DFT formula for X k X_k Xk​ is simply that X k = x ⋅ v k , X_k = x \cdot v_k, Xk​=x⋅vk​, where x x x is the vector ( x 0 , x 1 , … , x N − 1 ) .

How do you calculate DFT frequency?

calculate the magnitude of each DFT output bin: magnitude = sqrt(re*re+im*im) find the bin with the largest magnitude, call its index i_max . calculate the equivalent frequency of this bin: freq = i_max * Fs / N , here Fs = sample rate (Hz) and N = no of points in FFT.

How is DFT calculated in FFT?

fft , with a single input argument, x , computes the DFT of the input vector or matrix. If x is a vector, fft computes the DFT of the vector; if x is a rectangular array, fft computes the DFT of each array column. Compute the DFT of the signal and the magnitude and phase of the transformed sequence.