class="extype">Double</span>]</span>
      </span>
      </h4>
      <p class="shortcomment cmt">Sample standard deviation of each column
</p>
    </li><li visbl="pub" name="org.saddle.stats.FrameStats#sum" data-isabs="false">
      <a id="sum((org.saddle.Series[_, T]) ⇒ VecStats[T]):Series[CX, T]"></a>
      <h4 class="signature">
      <span class="modifier_kind">
        <span class="modifier"></span>
        <span class="kind">def</span>
      </span>
      <span class="symbol">
        <span class="n