rgin&lt;3, ak=[]; <span class="keyword">end</span>
0012 <span class="keyword">if</span> nargin&lt;4, n=0; <span class="keyword">end</span>
0013 <span class="keyword">if</span> isempty(ak),
0014 <span class="comment">%   cc=-curvature(rho,eta,1);</span>
0015     cc=<a href="curvature.html" class="code" title="function curv=curvature(x,y,n,t)">curvature</a>(rho/max(rho),eta/max(eta));
0016 <span class="keyword">else</span>
0017 <span class="comment">%   cc=curvature(rho/max(rho),eta/max(eta),n,ak);</span>
001