e series or arrays to analyze</span>

<span class="sd">    Returns</span>
<span class="sd">    -------</span>
<span class="sd">    mse : float</span>
<span class="sd">        Mean squared error</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="p">((</span><span class="n">predictions</span> <span class="o">-</span> <span class="n">targets</span><span class="p">)</span> <span class="o">**</span> <span class="mi">2</span><span class="p">)</span><span class="o"