Other options

Finally, I tested the inclusion of niching Goldberg and Richardson (1987) and elitism. The top panels of Figure  compare the convergence rates with niching and elitism (left)i, only elitism (middle), and only niching (right). The bottom panels show a similar comparison for the trace match. All the other evolution parameters were chosen according to the previous analysis. It seems that the lack of niching makes the convergence a little slower in the first iterations (compare the left and middle panels) but makes it faster after about the 40th generation. The lack of elitism, on the other hand, makes convergence a little erratic (compare left and right panels) since we are not guaranteed to go to a better-fit best individual in any generation compared with the previous one. Elitism was thus included and niching excluded in the evolution parameters of the final optimum standard genetic algorithm.

 

SG_compare_other1
Figure 8 Comparison of results for the inclusion of niching and elitism. Top panel convergence rates: left with niching and elitism, middle with elitism only and right with niching only. Bottom panels show similar comparison for the trace match with continuous line representing the reference trace and dotted line the inverted trace.