blob: ae9a59170e379810c4cc680de31242de21d84597 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
function y = ifftn(A, SIZE)
// Description
// Compute the inverse N-dimensional discrete Fourier transform of A using a Fast Fourier Transform (FFT) algorithm.
// The optional vector argument SIZE may be used specify the dimensions of the matrix to be used.
// If an element of SIZE is smaller than the corresponding dimension of A, then the dimension of A is truncated prior to performing the inverse FFT.
// Otherwise, if an element of SIZE is larger than the corresponding dimension then A is resized and padded with zeros.
// Calling Sequence
// Y = ifftn(A)
// Y = ifftn(A, size)
// Parameters
// A: Matrix
// SIZE : (optional) dimension of matrix to be used
// Examples
// ifftn([2,3,4])
// ans =
// 3. - 0.5 - 0.2886751i - 0.5 + 0.2886751i
funcprot(0);
funcprot(0);
rhs = argn(2)
if(rhs<1 | rhs>2)
error("Wrong number of input arguments.");
end
select(rhs)
case 1 then
y=fft(A,1);
case 2 then
// Check if A needs resizing
if size(A) == SIZE then
// No resizing needed
break;
elseif length(size(A)) ~= length(SIZE) then
error("Output size must have at least Ndims");
else
// Resize A using the resize_matrix function
A = resize_matrix(A, SIZE);
end
y = fft(A,1);
end
y = clean( y ) ;
endfunction
|
