March 2016


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Sean Luke <[log in to unmask]>
Reply To:
ECJ Evolutionary Computation Toolkit <[log in to unmask]>
Thu, 31 Mar 2016 16:08:46 -0400
text/plain (38 lines)
Actually, it's a bug in the first generation loop of CMA-ES: we were not scaling the covariance matrix by sigma, but rather leaving it as the identity matrix the first time around.  This is a minor bug but could result in CMA-ES going into, effectively, an infinite loop as it tries and fails to generate individuals within unusual min/max gene bounds.

We've fixed it as follows.  First, we fixed the bug.  Secondly, we added the ability to prescale the covariance matrix by min/max gene bounds to reduce the loop time; and third, we added an alternative individual-generation process to further reduce loop time.  See the manual for more explanation.

Anyway, fix pushed out.


On Mar 30, 2016, at 9:59 AM, Sean Luke <[log in to unmask]> wrote:

> This doesn't appear to be due to segments, but rather due to the small min/max range of the segments, which is causing an inordinate number of invalid individuals.  However that should *not* be an issue, so we'll look into what the initialization issue is.
> Sean
> Begin forwarded message:
>> From: "Eric 'Siggy' Scott" <[log in to unmask]>
>> Subject: CMA-ES hangs when segments are used
>> Date: March 29, 2016 at 9:45:49 PM EDT
>> To: [log in to unmask]
>> Reply-To: ECJ Evolutionary Computation Toolkit <[log in to unmask]>
>> Using the latest snapshot from GitHub, I find that, if I use segments in my genome, CMA-ES silently gets stuck before the first generation is evaluated.
>> Attached is a MWE.
>> I'm guessing that some background thread has silently crashed while the main thread was waiting for it?
>> Siggy
>> -- 
>> Ph.D student in Computer Science, George Mason University
>> CFO and Web Director, Journal of Mason Graduate Research