rs.</li>
            </ul>
         </div>
         <h2>Models<a name="2"></a></h2><pre class="codeinput">  n = [101, 101];
  d = [20, 20];
  o = [0, 0];

  vel    = 2*ones(n);
  velini = vel;
  <span class="keyword">for</span> i = 1:n(1)
    <span class="keyword">for</span> j = 1:n(2)
      <span class="keyword">if</span> norm([i-51,j-51])&lt;18
          vel(i,j) = 2.25;
      <span class="keyword">end</span>
    <span class="keyword">end</span>
  <span class="keyword">end</span>
<span class="comment">%</