cfft1di,zfft1di(3F)					   cfft1di,zfft1di(3F)

NAME    [Toc]    [Back]

     cfft1di, zfft1di -	initialize the coefficient array for Complex-toComplex
 1D	FFT modules.

SYNOPSYS    [Toc]    [Back]

     FORTRAN SPECIFICATION
     subroutine	CFFT1DI( n, coeff )
     integer		 n
     complex		 coeff(n+15)

     subroutine	ZFFT1DI( n, coeff )
     integer		 n
     double complex	 coeff(n+15)

     C SPECIFICATION
     #include <fft.h>
     complex *cfft1di( int n, complex *coeff);

     zomplex *zfft1di( int n, zomplex *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	cfft1d or zfft1d only read the coeff array, it may be
     reused as long as necessary once it has been initialized.

     In	C, if ptr is NULL, cfft1di or zfft1di returns a	pointer	to an
     allocated buffer.

     CFFT1DI should be used to initialize the coeeficient array	before any
     call to CFFT1D
     ZFFT1DI should be used to initialize the coeeficient array	before any
     call to ZFFT1D

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 complex-to-complex FFTs of size 200.

     Fortran :
	  complex coeff(200+15)
	  call cfft1di(	200, coeff)

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



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cfft1di,zfft1di(3F)					   cfft1di,zfft1di(3F)



	 coeff = cfft1di( 200, NULL);

SEE ALSO    [Toc]    [Back]

	  fft, cfft1d, zfft1d


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