uarantees.  The <em>only</em> way to allocate aligned
memory in standard Fortran is to allocate it with an external C
function, like the <code>fftw_alloc_real</code> and
<code>fftw_alloc_complex</code> functions.  Fortunately, Fortran 2003 provides
a simple way to associate such allocated memory with a standard Fortran
array pointer that you can then use normally.

   <p>We therefore recommend allocating all your input/output arrays using
the following technique:

     <ol type=1 start=1>

     <li>Declare 