DiversitySelector for symbolic data analysis problems

[bburlacu]

The diversity selector wraps any other selection operator (proportional, tournament, etc), but instead of selecting based on fitness it selects based on population diversity (calculated using the hash-based similarity measure).

Preliminary testing suggests that this selection method works quite well in combination with other selectors (eg as a male selector in gender-specific selection) or with offspring selection.

[bburlacu]

r16623: DiversitySelector initial implementation. A weight parameter was added to control the importance of the diversity term. Final "diversity" value computed as w * diversity + (1 - w) * fitness (similar for minimization).

r16626: Add plugin dependency to Plugin.cs.frame

[gkronber]

Reviewed r16623 and r16626. I'm not sure what this code is supposed to accomplish:

  private void CopySelected_ValueChanged(object sender, EventArgs e) {
    if (CopySelected.Value != true) {
      CopySelected.Value = true;
    }
  }

Otherwise the changes are fine. I tested the DiversitySelector and did not get any errors.

[bburlacu]

Replying to gkronber:

Reviewed r16623 and r16626. I'm not sure what this code is supposed to accomplish:

  private void CopySelected_ValueChanged(object sender, EventArgs e) {
    if (CopySelected.Value != true) {
      CopySelected.Value = true;
    }
  }

Otherwise the changes are fine. I tested the DiversitySelector and did not get any errors.

Originally, the DiversitySelector tried to prevent crossover between too similar individuals, so I adapted it from the NoSameMatesSelector. The snippet in question is an artifact from there and should probably be removed.

[gkronber]

r16839: made sure CopySelected is really always true

[abeham]

Merging the changes results in a conflict with #2971 as both make changes to the .csproj file.

[abeham]

r17140: merged to stable

• fixed merge conflict (order of items added to csproj, first DiversitySelector.cs, then SymbolicDataAnalysisExpressionTreeAverageSimilarityCalculator.cs