># Only change values at the column Change</span>
<span class="fu"><a href="https://rdrr.io/r/utils/head.html" class="external-link">head</a></span><span class="op">(</span><span class="fu"><a href="reference/recode_as_na.html">recode_as_na</a></span><span class="op">(</span><span class="va">another_dummy</span>, subset_cols <span class="op">=</span> <span class="st">"Change"</span>, value <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><s