"><pre class="sourceCode r"><code><span><span class="fu">sf_linestring</span><span class="op">(</span></span>
<span>  obj <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  x <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  y <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  z <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  m <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  linestring_id <span class="