scfft1dui,dzfft1dui(3F)				       scfft1dui,dzfft1dui(3F)

NAME    [Toc]    [Back]

     scfft1dui,	dzfft1dui - initialize the coefficient array for real-tocomplex
 1D	FFT modules.

SYNOPSYS    [Toc]    [Back]

     FORTRAN SPECIFICATION
     subroutine	SCFFT1DUI( n, coeff )
     integer		      n
     real	    coeff(n+15)

     subroutine	DZFFT1DUI( n, coeff )
     integer		      n
     real*8		 coeff(n+15)

     C SPECIFICATION
     #include <fft.h>
     float *scfft1dui( int n, float *coeff);

     double *dzfft1dui(	int n, double *coeff);

DESCRIPTION    [Toc]    [Back]

     Initialize, the coefficient array which is	used in	the FFT	modules.  This
     array contains the	different twiddle factors and the factorization	of N
     into prime	numbers.
     As	the FFT	modules	scfft1d	or dzfft1d only	read the coeff array, it may
     be	reused as long as necessary once it has	been initialized.

     In	C, if ptr is NULL, scfft1dui or	dzfft1dui returns a pointer to an
     allocated buffer.

     SCFFT1DUI should be used to initialize the	coefficient array before any
     call to SCFFT1DU
     DZFFT1DUI should be used to initialize the	coefficient array before any
     call to DZFFT1DU

PARAMETERS    [Toc]    [Back]

     N - Integer. Specifies the	length of the sequence to be transformed.
      Unchanged	on exit.

     COEFF - Array (C or Fortran) or NULL pointer(C).

Example	of Calling Sequence
     Initializing a coefficient	array for real-to-complex FFTs of size 200.

     Fortran :
	  float	coeff(200+15)
	  call scfft1dui( 200, coeff)

     C :
	  #include <fft.h>
	  float	*coeff;



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scfft1dui,dzfft1dui(3F)				       scfft1dui,dzfft1dui(3F)



	 coeff = scfft1dui( 200, NULL);

SEE ALSO    [Toc]    [Back]

	  fft, scfft1du, dzfft1du


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