Status changed from New to Refused
The explanation of this behavior is simple - you have 5727 strategies in initial population, and you generate 4 islands with 1440 strategies each.
Because initial population is bigger than the required population of the island these 1440 strategies for each island are chosen randomly from the initial population.
So there is no guarantee that these 5 strategies with the highest fitness 0.85 will be picked for any given island. If they were picked elitism would keep them in the population.
"The explanation of this behavior is simple - you have 5727 strategies in initial population, and you generate 4 islands with 1440 strategies each.
Because initial population is bigger than the required population of the island these 1440 strategies for each island are chosen randomly from the initial population.
So there is no guarantee that these 5 strategies with the highest fitness 0.85 will be picked for any given island. If they were picked elitism would keep them in the population."
geektrader has shown a screenshot of the RESULTS tab, he's wondering why the RESULTS are coming out lower. 1440x4 is 5760 of second build task room which is more than enough room for the 5727 no strats need to be randomly selected, instead some will need to be generated. geektrader is expecting to see all 5727 to appear in the results tab immediately since they all pass the ranking filters of the second build task. I think he's also expecting to see even better strategies coming out from that task in to the results tab and so would I.
"bendx77 - there is no drawback in SQ genetic evolution algorithm, it uses elitism and it works corectly."
Yes elitism works as intended and works very very excellent for low quality init pops like the way most people are probably using it. BTW I wasn't JUST talking about elitism. My point was that the killing off of parents so swiftly cannot be optimal for high quality start pops even though it seems to be good for low quality start pops. Apparently, I'm not the only one finding this. Think about this: the higher the finesses of the entire pool, the more likely they are to produce worse (than the original) children and or mutations so the more likely the fitness is to stagnate AND the more likely good high quality genes in the pool (even the worst in the pool could be good quality) will be replaced by worse genes. Assuming we are not in curve fit territory yet and assuming we still have room for improvements, it's prudent to allow the originals to live longer in such situations, even the worse genes in the pool which are quite high fitness in this case. By definition elitism must kill something to make room for the protective copies of the top genes, this may not be best in such a high quality start population setting where we are trading off too much for too little.
Or think in terms of value: The higher fitness we get in the pool, the value of the freshly generated mutations goes down (because they are less likely to best their parents) the value of the worse genes in such a pool can actually be quite high, nearly as high as the best genes, and so we don't necessarily want to trade them off so aggressively for the less valuable offspring and mutations. In fact, as we get higher in fitness (of the worse genes in the pool,) there must be an inflection point where we should instead be killing off the fresh mutations and offspring more aggressively (and the lower end of the pool less aggressively.)
In a low quality start pop, the lowest fitness in the pool are very low value and the fresh mutations and children are much more likely to best their parents and are much higher value so the current algo works awesome in this context.
Hi Guys,
"geektrader has shown a screenshot of the RESULTS tab, he's wondering why the RESULTS are coming out lower. 1440x4 is 5760 of second build task room which is more than enough room for the 5727 no strats need to be randomly selected, instead some will need to be generated. geektrader is expecting to see all 5727 to appear in the results tab immediately since they all pass the ranking filters of the second build task. I think he's also expecting to see even better strategies coming out from that task in to the results tab and so would I."
^ Exactly that! Anything else is a non-correct implementation of a genetic evolution algo, sorry. I am working with several other platforms, and exactly the above behavior is the case there if starting with such a initial population.