 a peak if its value is the largest among its four nearest</span>
<span class="sd">    neighbours.</span>

<span class="sd">    Parameters</span>
<span class="sd">    ----------</span>
<span class="sd">    X : np.ndarray [shape=(K, )] , complex-valued</span>
<span class="sd">        An FFT vector.</span>

<span class="sd">    Returns</span>
<span class="sd">    -------</span>
<span class="sd">    peaks : np.ndarray [shape=(P, )] , real-valued</span>
<span class="sd">        Vector with P peaks found</span>
