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-rw-r--r--macros/fft21.sci102
1 files changed, 57 insertions, 45 deletions
diff --git a/macros/fft21.sci b/macros/fft21.sci
index 2f04200..ee73a6b 100644
--- a/macros/fft21.sci
+++ b/macros/fft21.sci
@@ -1,45 +1,57 @@
-function res = fft21 (A, m, n)
-//Calculates the two-dimensional discrete Fourier transform of A using a Fast Fourier Transform algorithm.
-//Calling Sequence
-//fft2 (A, m, n)
-//fft2 (A)
-//Parameters
-//A: input matrix
-//m: number of rows of A to be used
-//n: number of columns of A to be used
-//Description
-//This is an Octave function.
-//It performs two-dimentional 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.
-//Examples
-//x = [1 2 3; 4 5 6; 7 8 9]
-//m = 4
-//n = 4
-//fft21 (A, m, n)
-//ans =
-//
-// 45 + 0i -6 - 15i 15 + 0i -6 + 15i
-// -18 - 15i -5 + 8i -6 - 5i 5 - 4i
-// 15 + 0i -2 - 5i 5 + 0i -2 + 5i
-// -18 + 15i 5 + 4i -6 + 5i -5 - 8i
-
-funcprot(0);
-lhs = argn(1)
-rhs = argn(2)
-if (rhs < 1 | rhs > 3)
-error("Wrong number of input arguments.")
-end
-
-select(rhs)
-
- case 1 then
- res = callOctave("fft2", A)
-
- case 2 then
- error("Wrong number of input arguments.")
-
- case 3 then
- res = callOctave("fft2", A, m, n)
-
- end
-endfunction
+/* Description
+ Calculates the two-dimensional discrete Fourier transform of A using a Fast Fourier Transform algorithm.
+ It performs two-dimentional FFT on the matrix A. You can use the variables m and n to specify the number of rows and columns
+ of A that you want to use. If either of these variables is larger than the size of A,
+ then A will be resized, and zeros will be added as padding.
+ If A is a multi-dimensional matrix, the function will treat each two-dimensional sub-matrix of A separately.
+ Calling Sequence
+ fft21 (A)
+ fft21 (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
+ fft21 (A, m, n)
+ ans =
+ 45 + 0i -6 - 15i 15 + 0i -6 + 15i
+ -18 - 15i -5 + 8i -6 - 5i 5 - 4i
+ 15 + 0i -2 - 5i 5 + 0i -2 + 5i
+ -18 + 15i 5 + 4i -6 + 5i -5 - 8i */
+function res = fft21 (A, m, n)
+ funcprot(0);
+ lhs = argn(1)
+ rhs = argn(2)
+ if (rhs < 1 | rhs > 3)
+ error("Wrong number of input arguments.")
+ end
+ siz=size(A)
+ len=length(siz)
+ select(rhs)
+ case 1 then
+ if len>2 then
+ last_dim=siz(len)
+ else
+ last_dim=1
+ end
+ res=[]
+ for i=1:last_dim
+ res(:,:,i)=fft(A(:,:,i),-1)
+ end
+ case 2 then
+ error("Wrong number of input arguments.")
+ case 3 then
+ if len>2 then
+ last_dim=siz(len)
+ else
+ last_dim=1
+ end
+ res=[]
+ for i=1:last_dim
+ res(:,:,i)=fft(resize_matrix(A(:,:,i),m,n),-1)
+ end;
+ end
+endfunction