TOFT (Inverse Discrete Fourice Transform)

IDFT $x(n)=\frac{1}{N} \sum_{k=0}^{N-k} \times \left(k) e^{\frac{j 2 \pi k}{N}} n\right.$

DFT $x(k)=\sum_{n=0}^{N-1} x(n) e^{-j \frac{2 \pi k}{N}} n$

DFT

$\left[\begin{array}{c}{x(0)} \\ {x(1)} \\ {x(2)} \\ {x(3)}\end{array}\right]\left[\begin{array}{cccc}{1} & {1} & {1} & {1} \\ {1} & {-j} & {x} & {j} \\ {1} & {-1} & …