text: #include <complex.h>
  #include <fftw3.h>
  
  #ifndef fftw_planxfftn_h 
  #define fftw_planxfftn_h
  
  typedef double fftw_real;
  
  fftw_plan fftw_planxfftn(int      ndims,
                           int      sizes_in[ndims],
                           void     *_in,
                           int      sizes_out[ndims],
                           void     *_out,
                           int      naxes,
                           int      axes[naxes],
                           int      kind[naxes],
                           unsigned flags);
  
  #endif
  