 .     .   1
#&gt;     Cyd 2.0 .     .   .
#&gt;     Dan .   1.0   1   .
#&gt; 
#&gt; $components
#&gt; $components$`3`
#&gt; [1] "Amy" "Ben" "Cyd" "Dan"
#&gt; 
#&gt; 
#&gt; attr(,"class")
#&gt; [1] "btdata" "list"  </div><div class='input'><span class='fu'>select_components</span>(<span class='no'>toy_btdata</span>, <span class='kw'>function</span>(<span class='no'>x</span>) <span class='fu'>length</span>(<span class='no'>x</span>) <span class='kw'>==</span> <span class='fl'>4</span>)</div><div class='outp