an class="va">long</span> <span class="op">&lt;-</span> <span class="fu">sparse2long</span><span class="op">(</span><span class="va">africa</span><span class="op">$</span><span class="va">comm</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="va">long</span><span class="op">[</span><span class="fl">1</span><span class="op">:</span><span class="fl">5</span>, <span class="op">]</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>   grids                