n class="o">=</span> <span class="n">numpy</span><span class="o">.</span><span class="n">exp</span><span class="p">(</span><span class="mi">1</span><span class="n">j</span> <span class="o">*</span> <span class="n">math</span><span class="o">.</span><span class="n">pi</span> <span class="o">*</span> <span class="n">frequency</span><span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">_frequency</span> <span class="o">=</span> <span class="n">frequency</span>

  