class="sd">&quot;&quot;&quot;Return a zero-initialized numpy array for the derivatives.&quot;&quot;&quot;</span>
        <span class="n">n_features</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_number_of_features</span><span class="p">()</span>
        <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">average</span> <span class="o">!=</span> <span class="s2">&quot;off&quot;</span><span class="p">:</span>
  