ile
Fortran&rsquo;s array dimensions are the opposite convention (column-major
order). See <a href="Multi_002ddimensional-Array-Format.html#Multi_002ddimensional-Array-Format">Multi-dimensional Array Format</a>.  This is just a
bookkeeping difference, with no effect on performance.  The only
consequence of this is that, whenever you create an FFTW plan for a
multi-dimensional transform, you must always <em>reverse the
ordering of the dimensions</em>.
</p>
<p>For example, consider the three-dimensional (L&nb