<span class="n">A_i</span> <span class="o">=</span> <span class="n">A</span><span class="p">[:,</span> <span class="n">index</span><span class="p">]</span>
                <span class="n">x_i</span> <span class="o">=</span> <span class="n">projections</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="o">/</span> <span class="n">torch</span><span class="o">.</span><span class="n">dot</span><span class="p">(</span><span class="n">A_i</span><span class="p">,</span>