/span><span class="n">vstack</span><span class="p">((</span><span class="n">sample_index</span><span class="p">,</span> <span class="n">i_des</span><span class="o">.</span><span class="n">coords</span><span class="p">)))</span>
                    <span class="k">else</span><span class="p">:</span>
                        <span class="n">descriptors</span><span class="p">[</span><span class="n">i_sample</span><span class="p">]</span> <span class="o">=</span> <span class="n">i_des</span>
                <spa