js-keyword">in</span>% c(<span class="hljs-string">"NOUN"</span>))
dtf &lt;- document_term_frequencies(dtf, document = <span class="hljs-string">"topic_level_id"</span>, term = <span class="hljs-string">"lemma"</span>)
head(dtf)
</code></pre>
<pre><code class="hljs">   doc_id      term freq
<span class="hljs-attribute">1</span>:   1882   weekend    1
<span class="hljs-attribute">2</span>:   1882       end    1
<span class="hljs-attribute">3</span>:   1882 confiance    1
<span class="hljs-attribute">4</span>