s="w"> </span><span class="nb">present</span><span class="p">(</span><span class="n">threads</span><span class="p">))</span><span class="w"> </span><span class="k">then</span>
<span class="k">            result</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">FFTW_FFT_3D_threads</span><span class="p">(</span><span class="nb">signal</span><span class="p">,</span><span class="w"> </span><span class="n">threads</span><span class="p">)</span>
<span class="w">        