ckages/utils/topics/head'>tail</a></span>(<span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/colnames'>colnames</a></span>(<span class='no'>df</span>[<span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/lapply'>sapply</a></span>(<span class='no'>df</span>, <span class='no'>is.numeric</span>) <span class='kw'>&amp;</span> (!<span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/colnames'>colnames</a></span>(<span class='no'>df</span>)