r <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">800</span>, <span class="fl">800</span><span class="op">)</span>, radius <span class="op">=</span> <span class="fl">200</span><span class="op">)</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># move "pop1" to another location along a specified trajectory and saved the</span></span></span>
<span