Interesting question.  prepareToEvaluate has a different purpose than  
what you're looking for.  What you want to do is have the prototype  
Problem generate its test cases prior to being cloned each  
generation.  You could do this by overriding the  
Evaluator.evaluatePopulation method to call some method on the  
Problem and then calling super.evaluatePopulation.  Alternatively you  
could stick in a Statistics subclass into the Statistics chain which  
overrides its preEvaluationStatistics method to call the method on  
the Problem.


On Jun 24, 2008, at 10:42 AM, David R White wrote:

> Hi,
> I would like to create a single set of test cases for all  
> individuals in a generation, and still be able to use multithreaded  
> evaluation.
> Is it possible to do this in an elegant manner?  If I use  
> "prepareToEvaluate" then it will be called for each Problem  
> instance that is cloned, i.e. once for each thread, and as my test  
> cases are probabilistically selected I will end up with a different  
> set of tests cases for each thread, which I don't want!
> Any help appreciated,
> Thanks
> David
> --
> David R White
> PhD Student
> Dept of Computer Science
> University of York, UK.