span class="dv">0</span>,<span class="dv">45</span>,<span class="dv">90</span>,<span class="dv">45</span>,<span class="dv">0</span>,-<span class="dv">45</span>) 

<span class="kw">ggplot</span>(m, <span class="kw">aes</span>(angle, value)) +
<span class="st">  </span><span class="kw">facet_wrap</span>(~variable, <span class="dt">ncol=</span><span class="dv">2</span>) +
<span class="st">  </span><span class="kw">annotate</span>(<span class="st">"rect"</span>, <span class="dt">xmin=</span><span class="dv">180