/span>), .(thickness), 
    summarize, <span class="dt">angle =</span> angle[<span class="kw">which.min</span>(R)] *<span class="st"> </span><span class="dv">180</span>/pi, <span class="dt">min =</span> <span class="kw">min</span>(R))
<span class="kw">ggplot</span>(<span class="kw">melt</span>(minimum, <span class="dt">id =</span> <span class="st">"thickness"</span>)) +<span class="st"> </span><span class="kw">facet_grid</span>(variable ~<span class="st"> </span>., <span class="dt">scales =</span> <span cla