> <span class="k">return</span> <span class="n">np</span><span class="o">.</span><span class="n">arange</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nb">max</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">y_values</span><span class="p">(</span><span class="n">xs</span><span class="p">,</span> <span class="n">sd</span><span class="p">):</span>
    <span class="k">return</span> <span class="n">xs</span> <span class="o">+</span> <span c