used <code>fftwnd</code> to to specify strides
etcetera, you would instead specify these via <code>fftw_plan_many_dft</code>.
</p>
<p>The analogues to <code>rfftw_create_plan</code> and <code>rfftw_one</code> with
<code>FFTW_REAL_TO_COMPLEX</code> or <code>FFTW_COMPLEX_TO_REAL</code> directions
are <code>fftw_plan_r2r_1d</code> with kind <code>FFTW_R2HC</code> or
<code>FFTW_HC2R</code>, followed by <code>fftw_execute</code>.  The stride etcetera
arguments of <code>rfftw</code> are now in <code>fftw_plan_man