sfft3du,dfft3du(3F)					   sfft3du,dfft3du(3F)

NAME    [Toc]    [Back]

     dfft3du, sfft3du -	3D Real	to Complex Fast	Fourier	Transform.

FORTRAN	SPECIFICATION
     subroutine	DFFT3DU( job, n1, n2, n3, sequence, ld1, ld2, workspace	)
     integer		 job, n1, n2, n3, ld1, ld2
     double precision	 sequence(ld1,ld2,*), workspace(*)

     subroutine	SFFT3DU( job, n1, n2, n3, sequence, ld1, ld2, workspace	)
     integer		 job, n1, n2, n3, ld1, ld2
     real		 sequence(ld1,ld2,*), workspace(*)

     C SPECIFICATION
     int	dfft3du( int job, int n1, int n2, int n3,
			 double	*sequence, int ld1, int	ld2,
			 double	*workspace)

     int	sfft3du( int job, int n1, int n2, int n3,
			 float	*sequence, int ld1, int	ld2,
			 float	*workspace)

DESCRIPTION    [Toc]    [Back]

     DFFT3DU and SFFT3DU compute the 3 dimensional complex Fourier transform
     of	a real periodic	sequence.

     NOTE: These routines are provided only for	compatibility with previous
     releases of complib.

PARAMETERS    [Toc]    [Back]

     JOB - INTEGER
     On	entry specifies	whether	to perform a forward or	backward Fast Fourier
     Transform:
	 JOB = -1,  forward FFT
	 JOB =	1,  backward FFT Unchanged on exit.

     N1	- INTEGER.
     On	entry, N1 specifies the	number of elements in the first	dimension of
     the sequence.  Unchanged on exit.

     N2	- INTEGER.
     On	entry, N2 specifies the	number of elements in the second dimension of
     the sequence.  Unchanged on exit.

     N3	- INTEGER.
     On	entry, N3 specifies the	number of elements in the third	dimension of
     the sequence.  Unchanged on exit.

     SEQUENCE -	Array.
     Array of DIMENSION	( LD1, LD2, n3 ).  Array containing the	(ld1*ld2*n3)
     elements for the FFT.  On exit, SEQUENCE is overwritten by	the 3D
     transform.



									Page 1






sfft3du,dfft3du(3F)					   sfft3du,dfft3du(3F)



     LD1 - INTEGER.    [Toc]    [Back]
     On	entry, LD1 specifies the first dimension of the	array SEQUENCE as
     declared in the calling (sub)program. LD1 must be at least	max( 1,
     2*((n1+2)/2) ).  Unchanged	on exit.

     LD2 - INTEGER.    [Toc]    [Back]
     On	entry, LD2 specifies the second	dimension of the array SEQUENCE	as
     declared in the calling (sub)program. LD2 must be at least	max( 1,	n2 ).
     Unchanged on exit.

     WORKSPACE - Array.    [Toc]    [Back]
     Array of dimension	at least (N1+15) + 2*(N2+15) + 2*(N3+15).  Array
     containing	the Sines/Cosines and factorization of N1, N2 and N3.
     WORKSPACE needs to	be initialized by a call to sfft3dui or	dfft3dui.

SEE ALSO    [Toc]    [Back]

     o32fft


									PPPPaaaaggggeeee 2222