Help files and functions

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+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