span> <span class="comment">%or /2 ?</span>
0030 <span class="keyword">if</span> isempty(dx), dx=dxel; <span class="keyword">end</span>
0031 dx=round(dx*20)/20;
0032 dy=round(dy*20)/20;
0033 <span class="keyword">if</span> nargin&lt;3,
0034     refx=round(dx/2/(Mod.z(2)-Mod.z(1)))*2;
0035 <span class="keyword">else</span>
0036     refx=1;
0037 <span class="keyword">end</span>
0038 <span class="keyword">if</span> refx&lt;1, refx=1; <span class="keyword">end</span>
0039 Mod.dx=dx/refx;
0040 <span class="keywo