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Author: Abinash Singh <abinashsinghlalotra@gmail.com>
*/
/*Description
Calculates the inverse two-dimensional discrete Fourier transform of A using a Fast Fourier Transform algorithm.
It performs inverse two-dimensional FFT on the matrix A. m and n may be used specify the number of rows and columns of A to use. If either of these is larger
than the size of A, A is resized and padded with zeros.
If A is a multi-dimensional matrix, each two-dimensional sub-matrix of A is treated separately.
Calling Sequence
ifft2 (A)
ifft2 (A, m, n)
Parameters
A: input matrix
m: number of rows of A to be used
n: number of columns of A to be used
Examples
A= [1 2 3; 4 5 6; 7 8 9]
m = 4
n = 4
ifft2 (A, m, n) --functionCall
ans =
2.81250 + 0.00000i -0.37500 + 0.93750i 0.93750 + 0.00000i -0.37500 - 0.93750i
-1.12500 + 0.93750i -0.31250 - 0.50000i -0.37500 + 0.31250i 0.31250 + 0.25000i
0.93750 + 0.00000i -0.12500 + 0.31250i 0.31250 + 0.00000i -0.12500 - 0.31250i
-1.12500 - 0.93750i 0.31250 - 0.25000i -0.37500 - 0.31250i -0.31250 + 0.50000i
*/
function res = ifft2(A, m, n)
funcprot(0);
lhs = argn(1)
rhs = argn(2)
if (rhs < 1 | rhs > 3)
error("Wrong number of input arguments.")
end
size_x=size(A)
len=length(size_x)
//to figure out size of multidimensional array
if len>2 then
last_dim=size_x(len)
else
last_dim=1
end
select(rhs)
case 1 then
res=[]
for i=1:last_dim //treating each submatrix seperately
res(:,:,i)=fft(A(:,:,i),1)
end
case 2 then
error("Wrong number of input arguments.")
case 3 then
res=[]
for i=1:last_dim
res(:,:,i)=fft(resize_matrix(A(:,:,i),m,n),1)
end
end
endfunction
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