 class="fl">90</span>, <span class="fl">90</span>, by <span class="op">=</span> <span class="fl">10</span><span class="op">)</span><span class="op">*</span><span class="va">pi</span><span class="op">/</span><span class="fl">180</span></span>
<span></span>
<span><span class="va">Z</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/expand.grid.html" class="external-link">expand.grid</a></span><span class="op">(</span>x <span class="op">=</span> <span class="va">x</span>, y <