David, take a look at ec/app/SimpleXYSeriesChartStatistics.java.  In  
there, note that it calls addDataPoint every once in a while, passing  
it the fitness it's computed after evaluation.

You can modify this in a straightforward fashion, by just gathering  
the average fitness over the individuals in the populations rather  
than gathering the best fitness.

Sean

On Feb 5, 2008, at 1:59 PM, David vun Kannon wrote:

> What is the best way to chart mean fitness per generation instead  
> of best fitness? If I want to calculate my own arbitrary statistic  
> on the population each generation and chart it, what do I need to  
> do in Statistics? Also, is there a way to chart the average of a  
> statistic over a set of runs?
>
> Thanks,
> David vun Kannon