ed&#39; between two series.</span>

<span class="sd">    For time series where the targets are serially correlated and may span only a fraction</span>
<span class="sd">    of the natural variability, this statistic may not be appropriate and Murphy (1988) explains</span>
<span class="sd">    why caution should be exercised in using this statistic.</span>

<span class="sd">    Parameters</span>
<span class="sd">    ----------</span>
<span class="sd">    predictions, targets : array_like</span>
<span class="s