HP 49G User Manual page 194

IFFT
1-194
2πikn
N 1 –
-------------- -
1
∑
--- -
X = Y e
n k
N
k = 0
M 1 – N 1 –
2πikm
----------------
1
∑ ∑
-------- -
X = Y e
mn kl
MN
k = 0 l = 0
N
i ,
= 1 –
2πi ln
----------------- -
i ,
M N
e = 1 –
Command Reference: Part C, G-P (1.1)