><span class="op">[[</span><span class="va">x</span><span class="op">]</span><span class="op">]</span><span class="op">[</span><span class="fl">1</span><span class="op">:</span><span class="fl">3</span><span class="op">]</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>      testdataset testgroup/testdataset2 testgroup1/testset1 testgroup2/testset2</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [1,]           1                      1         