  complete <span class="op">=</span> <span class="cn">FALSE</span>,</span>
<span>  fill <span class="op">=</span> <span class="fl">0</span>,</span>
<span>  return_matrix <span class="op">=</span> <span class="cn">TRUE</span>,</span>
<span>  orig <span class="op">=</span> <span class="st">"orig"</span>,</span>
<span>  dest <span class="op">=</span> <span class="st">"dest"</span>,</span>
<span>  flow <span class="op">=</span> <span class="st">"flow"</span></span>
<span><span class="op">)</span></span></code><