putes gains and losses as simple counts<br>
</li>
<li>
<code>total</code> calculates gains and losses as the sum of the quantity<br>
</li>
<li>
<code>value</code> measures the expected percentage gains and losses based on prices<br>
</li>
<li>
<code>duration</code> calculates the time in hours of held gains and losses.</li>
</ul>
<p>Instead, when method is set to “all”, then all the four measures are computed.</p>
<div class="sourceCode" id="cb17"><pre class="downlit sourceCode r">
<code class="sourceCo