 class="input_area">
<div class=" highlight hl-ipython3"><pre><span></span><span class="k">def</span> <span class="nf">categories</span><span class="p">(</span><span class="n">n</span><span class="p">):</span> 
    <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="n">n</span><span class="p">)</span>

<span class="k">def</span> <span class="nf">heights</span><span class="p">(</span><span class="n">xs</span><span cl