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Package offt (in offt.i) -

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DOCUMENT obj= offt(ljdir=,rjdir=,dims=,usefftw=,inplace=)

  Return a new FFT operator object and initialize workspace
  to compute FFT using Yorick's builtin Swarztrauber FFT, or
  using the yfftw FFTW plugin-- the "fastest FFT in the West."

  Keyword DIMS can be used to pre-specify the dimension list of the
  arrays to be transformed.  If left unspecified, the dimension
  list is initialized with the workspace the first time the
  transform operator is applied.  In all cases, an
  operator can only be used on arrays with same dimension lists,
  and the same target dimension (same as FFTW, and more restrictive
  than builtin fft for which workspace in not direction or array- 
  geometry specific.)  
  with usefftw==1, all arrays with a leading dimension of 
  length 2 will be taken to be of type complex{float re;float im}

  with usefftw==1, the workspace has to be manually cleaned up to
  free up memory (a shortcoming of yfftw plug_in):  OBJ, reset=1;


      d= [2,12,32]; x=random_n(d)+1i*random_n(d);
      fto= offt(usefftw=1);
      fto, reset=1;

      fto= offt(dims=d,ljdir=1,usefftw=1,inplace=1)
      fto, x;
      fto, reset=1;

SEE ALSO: fftw, fft.