="n">irow</span>     <span class="o">=&gt;</span> <span class="n">mat</span><span class="p">%</span><span class="n">irow</span>
      <span class="n">jcol</span>     <span class="o">=&gt;</span> <span class="n">mat</span><span class="p">%</span><span class="n">jcol</span>
      <span class="n">jptr</span>     <span class="o">=&gt;</span> <span class="n">mat</span><span class="p">%</span><span class="n">jptr</span>

      <span class="n">irow</span><span class="p">(</span><span class="mi">1</span><span class