hat we need to map the
calculated x value (<code>stat(x)</code>) onto the fill aesthetic, not
the original temperature variable. This is the case because
<code>geom_density_ridges_gradient</code> calls
<code>stat_density_ridges</code> (described in the next section) which
calculates new x values as part of its density calculation.</p>
<div class="sourceCode" id="cb14"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="fu"><a href="https://ggplot2.tidyverse.org/reference/ggplot.