   
0183         <span class="keyword">if</span> (i_past&gt;= L+1)
0184             time_d = time_d+ts; <span class="comment">% move forward one time step</span>
0185         <span class="keyword">end</span>
0186         
0187         <span class="keyword">if</span> i_transient&lt;L
0188             donen(1:i_transient-1) = 1;  <span class="comment">% we reuse what has been computed at the previous step</span>
0189             Un(:,1:i_transient-1) = Sys.system_data.U(:,1:i_transient-1); <span class="commen