Applying DFT twice does not actually reverse an array. Instead, the first element stays in place while the rest of the array is reversed. Why?

1. What happens if we apply DFT twice to a signal?
2. Why is the DFT mirrored?
3. What is DFT What are the advantages of computing DFT?
4. What is the disadvantage of direct computation of DFT?

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.

Why is the DFT mirrored?

Because both the positive and negative frequency sinusoids are 90 degrees out of phase and have the same magnitude, they will both respond to real signals in the same way.

What is DFT What are the advantages of computing DFT?

Advantages: The most significant advantage to DFT methods is a significant increase in computational accuracy without the additional increase in computing time. DFT methods such as B3LYP/6-31G(d) are oftentimes considered to be a standard model chemistry for many applications.

What is the disadvantage of direct computation of DFT?

For the computation of N-point DFT, N2 complex multiplications and N[N-1] Complex additions are required. If the value of N is large than the number of into lakhs. This proves inefficiency of direct DFT computation.