span>
<span class='no'>elements</span> <span class='kw'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/subset.html'>subset</a></span>(<span class='no'>elements</span>, !<span class='fu'><a href='https://rdrr.io/r/base/NA.html'>is.na</a></span>(<span class='no'>group</span>))
<span class='no'>elements</span>$<span class='no'>group</span> <span class='kw'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/character.html'>as.character</a></span>(<span class='no'>elements</span>$<span 