span>
<span class="sd">       fs (float): Sampling frequency of time series (equispaced).</span>

<span class="sd">    Returns:</span>
<span class="sd">       (array): xf and yf, x and y coordinate values for the FFT.</span>

<span class="sd">    &quot;&quot;&quot;</span>
    <span class="kn">from</span> <span class="nn">scipy.fftpack</span> <span class="kn">import</span> <span class="n">fft</span>
    <span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np