.  The only exceptions to this are the <code>FFTW_ESTIMATE</code> and
<code>FFTW_WISDOM_ONLY</code> flags, as mentioned below.
</p>
<p>In all  cases, if  wisdom is  available for the  given problem  that was
created  with equal-or-greater  planning rigor,  then the  more rigorous
wisdom is used.  For example, in <code>FFTW_ESTIMATE</code> mode any available
wisdom is used, whereas  in <code>FFTW_PATIENT</code> mode only wisdom created
in patient or exhaustive mode can be used.  See <a href="Words-of-Wisdom_