lass="nb">float</span><span class="p">(</span><span class="n">samples</span> <span class="o">-</span> <span class="mi">1</span><span class="p">))</span> <span class="o">*</span> <span class="mi">2</span>  <span class="c1"># y goes from 1 to -1</span>
        <span class="n">radius</span> <span class="o">=</span> <span class="n">math</span><span class="o">.</span><span class="n">sqrt</span><span class="p">(</span><span class="mi">1</span> <span class="o">-</span> <span class="n">y</span> <span class="o">*</s