BEST_FFT Name
      
       BEST_FFT Purpose
      
       Attempts to find size of fastest FFT from given choices.
Category
Calling Sequence
      
       m = best_fft(n) Inputs
             n = proposed FFT size.                         in
Keyword Parameters
Keywords
        
         DELTA=d  The range to search in samples or percent.
                      Default = +/-1.
        
         /PERCENT means DELTA is in percent of n.
        
         /DOWN  Search from n down to n-DELTA.
Outputs
      
       m = Predicted fastest FFT size within range.   out
Common Blocks
Notes
      
       Notes: the selection is made based on the prime factors
        
         of the possible values.  The largest prime factor of
        
         each candidate is determined and the value with the
        
         smallest max prime factor is considered the best to use.
        
         For multiple matches the one with the smallest sum
                  of the prime factors is selected.
Modification History
      
       R. Sterner, 8 Feb, 1993 
      
       R. Sterner, 2010 Apr 30 --- Converted arrays from () to []. 
  
 Copyright (C) 1993, Johns Hopkins University/Applied Physics Laboratory
  
 This software may be used, copied, or redistributed as long as it is not
  
 sold and this copyright notice is reproduced on each copy made.  This
  
 routine is provided as is without any express or implied warranties
  
 whatsoever.  Other limitations apply as described in the file disclaimer.txt.