 class="p">(</span><span class="n">start</span><span class="o">=</span><span class="n">start</span><span class="p">,</span> <span class="n">freq</span><span class="o">=</span><span class="n">intvl</span><span class="p">,</span> <span class="n">periods</span><span class="o">=</span><span class="mi">4000</span><span class="p">)</span>
    <span class="n">x</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">linspace</span><span class="p">(</span><span class="mi">0<