Merge pull request #17 from avinashlalotra/masterHEADmaster

Abinash's Work

1 files changed, 55 insertions, 45 deletions

diff --git a/macros/ifft2.sci b/macros/ifft2.sci
index 8ecb1a5..762631d 100644
--- a/macros/ifft2.sci
+++ b/macros/ifft2.sci
@@ -1,45 +1,55 @@
-function res = ifft2 (A, m, n)
-//Calculates the inverse two-dimensional discrete Fourier transform of A using a Fast Fourier Transform algorithm.
-//Calling Sequence
-//ifft2 (A, m, n)
-//ifft2 (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 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.
-//Examples
-//x = [1 2 3; 4 5 6; 7 8 9]
-//m = 4
-//n = 4
-//ifft2 (A, m, n)
-//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
-
-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("ifft2", A)
-
-	case 2 then
-	error("Wrong number of input arguments.")
-
-	case 3 then
-	res = callOctave("ifft2", A, m, n)
-
-	end
-endfunction
+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