span class="n">np</span><span class="o">.</span><span class="n">cov</span><span class="p">(</span><span class="n">dataset</span><span class="o">.</span><span class="n">T</span><span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">pm_cov</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">pm_cov</span> <span class="o">&lt;</span> <span class="bp">self</span><span class="o">.</span><span class="n">lower_bound</span><s