n></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># create a blank abstract world 1000x1000 distance units in size</span></span></span>
<span class="r-in"><span><span class="va">map</span> <span class="op">&lt;-</span> <span class="fu"><a href="world.html">world</a></span><span class="op">(</span>xrange <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">0</spa