span class="o">.</span><span class="n">min_f</span><span class="p">(),</span> <span class="bp">self</span><span class="o">.</span><span class="n">max_f</span><span class="p">()</span><span class="o">-</span><span class="n">L</span><span class="p">)</span>

        <span class="c1"># Distance matrix for this level</span>
        <span class="n">D</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">zeros</span><span class="p">(</span><span class="n">shape</span> <s