Merge pull request #17 from avinashlalotra/masterHEADmaster

Abinash's Work

1 files changed, 63 insertions, 49 deletions

diff --git a/macros/fft1.sci b/macros/fft1.sci
index a0a6438..f8a27fc 100644
--- a/macros/fft1.sci
+++ b/macros/fft1.sci
@@ -1,49 +1,63 @@
-function res =  fft1 (x, n, dim)
-//Calculates the discrete Fourier transform of a matrix using Fast Fourier Transform algorithm.
-//Calling Sequence
-//fft (x, n, dim)
-//fft (x, n)
-//fft (x)
-//Parameters 
-//x: input matrix
-//n: Specifies the number of elements of x to be used
-//dim: Specifies the dimention of the matrix along which the FFT is performed
-//Description
-//This is an Octave function.
-//The FFT is calculated along the first non-singleton dimension of the array. Thus, FFT is computed for each column of x.
-//
-//n is an integer specifying the number of elements of x to use. If n is larger than dimention along. which the FFT is calculated, then x is resized and padded with zeros.
-//Similarly, if n is smaller, then x is truncated.
-//
-//dim is an integer specifying the dimension of the matrix along which the FFT is performed.
-//Examples
-//x = [1 2 3; 4 5 6; 7 8 9]
-//n = 3
-//dim = 2
-//fft1 (x, n, dim)
-//ans =
-//
-//    6.0000 +  0.0000i   -1.5000 +  0.8660i   -1.5000 -  0.8660i
-//   15.0000 +  0.0000i   -1.5000 +  0.8660i   -1.5000 -  0.8660i
-//   24.0000 +  0.0000i   -1.5000 +  0.8660i   -1.5000 -  0.8660i
-
-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("fft", x)
-
-	case 2 then
-	res = callOctave("fft", x, n)
-
-	case 3 then
-	res = callOctave("fft", x, n, dim)
-
-	end
-endfunction
+/*Description

+        Calculates the discrete Fourier transform of a matrix using Fast Fourier Transform algorithm.

+        The FFT is calculated along the first non-singleton dimension of the array. Thus, FFT is computed for each column of D.

+        The variable 'N' is an integer that determines the number of elements of 'D' to use.

+        If 'N' is larger than the dimension along which the FFT is calculated,

+        then 'D' is resized and padded with zeros to match the required size.On the other hand,

+        if 'N' is smaller than the size of 'D', then 'D' is truncated to match the required size.

+        DIM is an integer specifying the dimension of the matrix along which the FFT is performed.

+Calling Sequence

+       fft1 (D)

+       fft1 (D, N)

+       fft1 (D, N, DIM)

+Parameters

+        D: input matrix

+        N: Specifies the number of elements of x to be used

+        DIM: Specifies the dimention of the matrix along which the FFT is performed

+Examples

+        D = [1 2 3; 4 5 6; 7 8 9]

+        N = 3

+        DIM = 2

+        fft1 (D,N,DIM)

+        ans =

+            6.0000 +  0.0000i   -1.5000 +  0.8660i   -1.5000 -  0.8660i

+            15.0000 +  0.0000i   -1.5000 +  0.8660i   -1.5000 -  0.8660i

+            24.0000 +  0.0000i   -1.5000 +  0.8660i   -1.5000 -  0.8660i */

+function res =  fft1 (D, N, DIM)

+    funcprot(0);

+    lhs = argn(1)

+    rhs = argn(2)

+    if (rhs < 1 | rhs > 3)

+        error("Wrong number of input arguments.")

+    end

+    dimension = size(D);

+    // first non-singleton dimension

+    nsdim = find(dimension >1,1)

+    if isempty(nsdim) then

+        nsdim = 1 // default to 1 to avoid error while calling fft

+    end    

+    select(rhs)

+    case 1 then

+        res = fft(D, -1, nsdim);

+    case 2 then

+        if isempty(N) then

+            n = size(D, nsdim);

+        else

+            n = N;

+        end

+        new_size = size(D);

+        new_size(nsdim) = n;

+        D = resize_matrix(D, new_size);

+        res = fft(D, -1, nsdim);

+    case 3 then

+        if isempty(N) then

+            n = size(D, DIM);

+        else

+            n = N;

+        end

+        new_size = size(D);

+        new_size(DIM) = n;

+        D = resize_matrix(D, new_size);

+        res= fft(D, -1, DIM);

+        end

+endfunction