an id="cb2-13"><a href="#cb2-13" tabindex="-1"></a>mask <span class="ot">&lt;-</span> vol <span class="sc">&gt;</span> <span class="dv">0</span></span>
<span id="cb2-14"><a href="#cb2-14" tabindex="-1"></a><span class="fu">cat</span>(<span class="st">&quot;Voxels above zero:&quot;</span>, <span class="fu">sum</span>(mask), <span class="st">&quot;</span><span class="sc">\n</span><span class="st">&quot;</span>)</span>
<span id="cb2-15"><a href="#cb2-15" tabindex="-1"></a><span class="co">#&gt; Voxels above ze