Chapter 14 MI5000: Exploitation rate results

Here we present the results for best performances found by each selection scheme replicate on the exploitation rate diagnostic with configurations presented below. For our the configuration of these experiments, we execute migrations every 50 generations and there are 4 islands in a ring topology. When migrations occur, we swap two individuals (same position on each island) and guarantee that no solution can return to the same island. Best performance found refers to the largest average trait score found in a given population. Note that performance values fall between 0.0 and 100.0.

14.2 Truncation selection

Here we analyze how the different population structures affect truncation selection (size 8) on the exploitation rate diagnostic.

14.2.3 Stats

Summary statistics for the first generation a satisfactory solution is found.

## # A tibble: 3 x 8
##   Structure count na_cnt   min median  mean   max   IQR
##   <fct>     <int>  <int> <int>  <dbl> <dbl> <int> <dbl>
## 1 EA          100      0  3382  3422  3421.  3473  26  
## 2 IS          100      0  4718  4788. 4786.  4834  40  
## 3 NMIS        100      0  4736  4783  4782.  4830  25.2

Kruskal–Wallis test provides evidence of difference among selection schemes.

## 
##  Kruskal-Wallis rank sum test
## 
## data:  Generations by Structure
## Kruskal-Wallis chi-squared = 200.03, df = 2, p-value < 2.2e-16

Results for post-hoc Wilcoxon rank-sum test with a Bonferroni correction.

## 
##  Pairwise comparisons using Wilcoxon rank sum test with continuity correction 
## 
## data:  ssf$Generations and ssf$Structure 
## 
##      EA     IS
## IS   <2e-16 - 
## NMIS <2e-16 1 
## 
## P value adjustment method: bonferroni

14.3 Tournament selection

Here we analyze how the different population structures affect tournament selection (size 8) on the exploitation rate diagnostic.

14.3.3 Stats

Summary statistics for the first generation a satisfactory solution is found.

## # A tibble: 3 x 8
##   Structure count na_cnt   min median  mean   max   IQR
##   <fct>     <int>  <int> <int>  <dbl> <dbl> <int> <dbl>
## 1 EA          100      0  5358  5456. 5453.  5526  41.8
## 2 IS          100      0  5819  5900  5903.  5973  40.8
## 3 NMIS        100      0  5821  5914  5912.  5977  41.8

Kruskal–Wallis test provides evidence of difference among selection schemes.

## 
##  Kruskal-Wallis rank sum test
## 
## data:  Generations by Structure
## Kruskal-Wallis chi-squared = 201.55, df = 2, p-value < 2.2e-16

Results for post-hoc Wilcoxon rank-sum test with a Bonferroni correction.

## 
##  Pairwise comparisons using Wilcoxon rank sum test with continuity correction 
## 
## data:  ssf$Generations and ssf$Structure 
## 
##      EA     IS  
## IS   <2e-16 -   
## NMIS <2e-16 0.04
## 
## P value adjustment method: bonferroni

14.4 Lexicase selection

Here we analyze how the different population structures affect standard lexicase selection on the exploitation rate diagnostic.

14.4.3 Stats

Summary statistics for the first generation a satisfactory solution is found.

## # A tibble: 3 x 8
##   Structure count na_cnt   min median   mean   max   IQR
##   <fct>     <int>  <int> <int>  <dbl>  <dbl> <int> <dbl>
## 1 EA          100      0 23129 25376  25814. 32119 1658.
## 2 IS          100      0 24579 27304. 27591. 34039 1903.
## 3 NMIS        100      0 24476 27170. 27601. 34985 1759.

Kruskal–Wallis test provides evidence of difference among selection schemes.

## 
##  Kruskal-Wallis rank sum test
## 
## data:  Generations by Structure
## Kruskal-Wallis chi-squared = 72.912, df = 2, p-value < 2.2e-16

Results for post-hoc Wilcoxon rank-sum test with a Bonferroni correction.

## 
##  Pairwise comparisons using Wilcoxon rank sum test with continuity correction 
## 
## data:  ssf$Generations and ssf$Structure 
## 
##      EA      IS
## IS   1.1e-13 - 
## NMIS 5.6e-13 1 
## 
## P value adjustment method: bonferroni