</code>
</figcaption>
</figure>
</div>
</div>
<p>As in <a href="#fig-cat-quant" class="quarto-xref">Figure&nbsp;<span class="quarto-unresolved-ref">fig-cat-quant</span></a>, mapping a <em>quantitative</em> variable to color makes the graph hard to read. To simplify, we’ve separated the data layer from the model layer.</p>
<p>It’s almost impossible to see the relationship between fathers and children’s heights in the data layer. By stripping away the child-to-child residuals, the model-value layer clar