[FRIAM] on selection pressure

[Marcus Daniels]

Here are a couple of plots from a large constrained optimization problem I've been running.   
In the first case, I apply selection pressure:  If a solution is not in the top 200 performers, it dies.
In the second case, the population can continue to grow without concern for its performance.   
This is a 5900-dimensional pseudo-boolean problem and the best-known solution is around 2.61e+08.   Note the low end of the y axis is not close to this.   In both cases, aggressive efforts are made to diversify the population and in both cases every shown solution is unique (even though their energies can collide). 

In this case, I would argue that selection pressure has accomplished nothing -- conservatism doesn't work if the goal is to create the most fit individuals.  The mean moves, if you care about that.   But the very best solutions are nearly the same, and neither have come close to the optimal.   

Marcus 



-------------- next part --------------
A non-text attachment was scrubbed...
Name: diversity.png
Type: image/png
Size: 6135 bytes
Desc: diversity.png
URL: <http://redfish.com/pipermail/friam_redfish.com/attachments/20190102/1aa86dfe/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: diversityNoPressure.png
Type: image/png
Size: 5434 bytes
Desc: diversityNoPressure.png
URL: <http://redfish.com/pipermail/friam_redfish.com/attachments/20190102/1aa86dfe/attachment-0001.png>