[galib] a notion of speed in GALib - RFC

philip tucker phhht at earthlink.net
Sat Jun 6 14:42:41 EDT 2009

For some time I've been thinking about how to get some measure, in  
some sense, of how fast a population of genomes is changing.

The units of this measure seem apparent: bits/generation.  Here's  
what I did.

For concreteness, let's take GAInc.  At the beginning of each step(),  
I save the current state of a
genome.  At the end of the step, I save the Hamming distance (in  
bits, not percent) between the original and current states of the  
genome.  At statistics report time, I report the speed as the  
arithmetic mean of the distances collected.

I'd like to hear from you with any comments you have.  In particular,  
is there a better or alternative  way to measure speed?  What's wrong  
with this way?

This technique also works for GASimple.  In GASState, the technique  
is complicated by uncertainity
that I am measuring the initial and final states of the same genome.   
But does that matter much?

Thanks very much for your comments.

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