ifft:

Syntax:	ifft ( X )
	ifft ( X , N )

Description:

	Ifft utilizes the FFTPACK subroutine CFFTB to compute a
	discrete Fourier transform of the input. The output is scaled
	by 1/N, so that a call to fft() followed by a call to ifft()
	will reproduce the original input. 

	If ifft is used with a second argument, N, then the matrix X
	is either padded with zeros, or truncated till it is of length
	N (if X is a vector), or has row dimension N (if it is a
	matrix).

	Subroutine CFFTB computes the backward complex discrete
	Fourier transform (the Fourier synthesis). equivalently, CFFTB
	computes a complex periodic sequence from its Fourier
	coefficients.

	for j=1,...,n

           c(j)=the sum from k=1,...,n of

               	 c(k)*exp(i*(j-1)*(k-1)*2*pi/n)

                     	 where i=sqrt(-1)

	The argument X must be a matrix. If X is a row, or column
	matrix then a vector ifft is performed. If X is a MxN matrix
	then the N columns of X are ifft'ed.

See Also: fft
