abel="anchor" href="#arg-alpha"></a></dt>
<dd><p>Numeric (0-1). Only used when bw and conditional are FALSE. Sets
the transparency of geom_density, so that classes with a small number of
cases remain visible.</p></dd>


<dt id="arg-facet-labels">facet_labels<a class="anchor" aria-label="anchor" href="#arg-facet-labels"></a></dt>
<dd><p>Named character vector, the names of which should
correspond to the facet labels one wishes to rename, and the values of which
provide new names for these facets. For example