;-</span> <span class='fu'>c</span>(<span class='fu'>rep</span>(<span class='st'>"a"</span>, <span class='fl'>10</span>), <span class='fl'>NA</span>, <span class='fl'>NA</span>)
<span class='no'>notSingularVar</span> <span class='kw'>&lt;-</span> <span class='fu'>c</span>(<span class='st'>"a"</span>, <span class='st'>"a"</span>, <span class='st'>"b"</span>, <span class='st'>"c"</span>, <span class='st'>"d"</span>, <span class='st'>"e"</span>, <span class='st'>"f"</span>, <span class='fl'>NA</span>, <span cl