cfftmi

NAME

CFFTMI - initialization routine for CFFTMB and CFFTMF

SYNOPSIS

 SUBROUTINE CFFTMI (N, WSAVE, LENSAV, IER)
 INTEGER    N, LENSAV, IER
 REAL       WSAVE(LENSAV)

DESCRIPTION

 FFTPACK 5.0 subroutine CFFTMI initializes array WSAVE for use in 
 its companion routines CFFTMB and CFFTMF.  Routine CFFTMI must 
 be called before the first call to  CFFTMB or CFFTMF, and after 
 whenever the value of integer N changes.
 
 Input Arguments
 
 N       Integer length of each sequence to be transformed.  The 
         transform is most efficient when N is a product of 
         small primes.
 
 LENSAV  Integer dimension of WSAVE array.  LENSAV must be at least 
         2*N + INT(LOG(REAL(N))) + 4.


 Output Arguments
 
 WSAVE   Real work array with dimension LENSAV, containing the
         prime factors of N and also containing certain trigonometric 
         values which will be used in routines CFFTMB or CFFTMF.


 IER     = 0 successful exit
         = 2 input parameter LENSAV not big enough