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| Syntax |
idft(z) |
| See Also | ifft , dft , ifft |
N is the number of rows in z,
the (k,j)-th element of the return value is equal to
N
1 ----- __
- > z exp[+2 pi \/-1 (i - 1) (k - 1) / N]
N ----- i,j
i = 1
k between 1 and N
and j between 1 and the number of columns in z.
z = {0, 1, 0, 0}
only the term with i = 2 in the summation defining
idft(z) is nonzero, and the k-th element of
idft(z) is equal to
1 __
- exp[+2 pi \/-1 (k - 1) / 4]
4
1/4,
\sqrt(-1)/4,
-1/4, and -\sqrt(-1)/4,
for k equal to 1, 2, 3, and 4, respectively.
If you continue this example by entering
idft(z)
O-Matrix will respond
{
(.25,0)
(0,.25)
(-.25,0)
(0,-.25)
}
ifft
instead of idft.
If you continue the example above by entering
mlmode
ifft(z)
O-Matrix will respond
{
(.25,0)
(0,.25)
(-.25,0)
(0,-.25)
}