andle to segment_space (see GCBO)</span>
0559 <span class="comment">% eventdata  reserved - to be defined in a future version of MATLAB</span>
0560 <span class="comment">% handles    structure with handles and user data (see GUIDATA)</span>
0561 
0562 NumZones = str2double(get(handles.num_zones,<span class="string">'String'</span>)); 
0563 <span class="keyword">if</span> NumZones &lt; 2
0564     errordlg(<span class="string">'Must have at least 2 zones'</span>,<span class="string">'Too few zones'</span>)
05