NEC-LIST: 4nec2 modeler:about the GA optimizer

Hi,everyone
      I am using the 4nec2 modeling software. Here I have several confusions to
 ask for help:
 
1. When I use the optimizer, I select the evolve algorithm and I want to optimize
the SWR over a band of frequencies. After setting the symbols and their bounds,
I have tried these steps:
       i) set the blank below SWR to be 100 and keep others 0;
       ii) select the checkbox "Freq-sweep" and set the frequency band;
       iii) right click on the SWR and choose the "Use Maximum" in the Freq-sweep
 option
       iv) click "start "
     when the optimization is running ,I found the results listed at the lower place
are not the ones I had expected. The best fitness in each generation shows the
SWR computed like this:
           i) average the input impedance over the freq-sweep
          ii) use the average impedance and the characteristic impedance 50 ohm to
compute the average SWR
 
however, I want to use the maximum SWR or the average SWR directly averaged
by the values at each frequency.I am puzzled why it is.
 
 I don't know whether the 4nec2 can support the customized fitness fun, which will
 bring more convience.
 
  
2. In general, how to design a broad-band antenna? I mean which parameters
should we choose as the fitness function.
 
3. Could I re-compile the source code to be a library for calling by other programs
and customize the output ?
 
Great thanks~
          
  sincerely ,xiaolin
  Wuhan, China
  01/12/09

-- 
The NEC-List mailing list
NEC-List_at_robomod.net
http://www.robomod.net/mailman/listinfo/nec-list