Fitness scores spike when changing fitness component weights or lifetime slider

What steps will reproduce the problem?
  1. Click deploy in NERO
  2. Adjust the sliders for a task (such as approach flag)
  3. Wait for a while to collect some datapoints in the plot window
  4. Either:
    * Adjust the lifetime slider to increase the lifetime dramatically, or
    * Change the fitness weights

What is the expected output? What do you see instead?

I expect the plot to be a meaningful representation of the population fitness. 
What happens instead is there is a spike of huge values immediately after 
change - this is because the old population average and standard deviation are 
no longer valid, but are still being used to calculate the Z-score of the 
currently evaluated individuals.

We should probably reset the population statistics on at least some of these 
changes. Currently this prevents us from doing any kind of shaping tasks.

Original issue reported on code.google.com by ikarpov on 23 Sep 2010 at 2:37

ggazzo / opennero

Fitness scores spike when changing fitness component weights or lifetime slider #41