Mu Plus Lambda EA

[francastagna]

PR Summary

Add (μ+λ) Evolutionary Algorithm

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(μ+λ) EA Pseudocode

Source: https://www.researchgate.net/publication/327166354_An_Empirical_Evaluation_of_Evolutionary_Algorithms_for_Unit_Test_Suite_Generation

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Main Changes

• EMConfig

  • Add MuPlusLambdaEA to EMConfig.Algorithm.
  • Add/Expose muPlusLambdaOffspringSize (λ) for (μ+λ) EA.

• Main wiring

  • Wire MuPlusLambdaEvolutionaryAlgorithm for all relevant problem types (GraphQL, RPC, Web, REST).

• New algorithm

  • MuPlusLambdaEvolutionaryAlgorithm.kt
    • For each generation: generate λ offspring via mutation from parents (λ/μ per parent), then select the best µ from parents ∪ offspring.

• Docs

  • Update docs/options.md to include MuPlusLambdaEA and muPlusLambdaOffspringSize.

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Tests

• MuPlusLambdaEvolutionaryAlgorithmTest.kt
  • Finds Optimum (testMuPlusLambdaEAFindsOptimum).
  • Edge cases:
    • xoverProbability=0.0, fixedRateMutation=1.0 → 0 crossovers, λ mutations, µ size preserved. (testNoCrossoverWhenProbabilityZero_MuPlusEA)
    • fixedRateMutation=0.0, xoverProbability=1.0 → 0 mutations, µ size preserved. (testNoMutationWhenProbabilityZero_MuPlusEA)
  • One-iteration properties (testSelectionBestMuAndMutationCount_MuPlusEA):
    • Final population size equals µ.
    • Final population equals top-µ by score from parents ∪ offspring.
    • With fixedRateMutation=1.0 and λ divisible by µ → mutations = λ.

[arcuri82]

@francastagna hi. this PR has conflicts that need to be resolved before review

[francastagna]

@francastagna hi. this PR has conflicts that need to be resolved before review

Hi Andrea! Thanks 👍🏽
I’ve just resolved the conflicts.