pr">#&gt;</span>    grids species</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1     g1     sp1</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2     g3     sp1</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3     g4     sp1</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 4     g1     sp2</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 5     g4     sp2</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 6     g5     sp2</spa