INVFFT

Syntax: INVFFT(R)

R = a range

INVFFT generates the inverse Discrete Fourier Transform or range R using a Fast Fourier Transform algorithm. The length of the vector must be a power of 2. INVFFT will produce the same results as INVDFT, but it is much faster ($N \log N$) time as opposed to $N^2$ time).

Examples:

Matrix A1..B4 =

	A	B
1	0.99	0
2	3	6.2
3	4.1	1.1
4	3.3	6.3

INVFFT(A1..B4) =

2.8475	3.4
-0.8025	-0.2
-0.3025	-2.85
-0.7525	-0.35

INVFFT(A1..F3) = Error - INVFFT, dimension must be power of 2

Excel function: N/A