Chromosome tests

.rubocop.yml

@@ -7,6 +7,9 @@ Style/StringLiterals:
 Metrics/LineLength:
   Max: 160
 
+Metrics/MethodLength:
+  Max: 35
+
 Gemspec/OrderedDependencies:
   Enabled: false
 

.vscode/settings.json

@@ -4,7 +4,12 @@
   "files.trimTrailingWhitespace": true,
   "files.insertFinalNewline": true,
   "ruby.lintDebounceTime": 500,
+  "ruby.useBundler": true,
+  "ruby.useLanguageServer": true,
   "ruby.lint": {
-    "rubocop": true
+    "rubocop": {
+      "useBundler": true
+    }
   },
+  "ruby.format": "rubocop"
 }

genetic-algorithm-resolver.gemspec

@@ -1,7 +1,7 @@
 
 lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
-require "genetic/algorithm/version"
+require "genetic/algorithm"
 
 Gem::Specification.new do |spec|
   spec.name          = "genetic-algorithm-resolver"

lib/genetic/algorithm.rb

@@ -1,4 +1,5 @@
 module Genetic
   module Algorithm
+    VERSION = "0.1.0".freeze
   end
 end

lib/genetic/algorithm/chromosome.rb

@@ -0,0 +1,21 @@
+# A member of a given population
+class Genetic::Algorithm::Chromosome
+  attr_accessor :genes
+  attr_accessor :fitness
+
+  def initialize(genes:, fitness:)
+    @genes = genes
+    @fitness = fitness
+  end
+
+  # Randomly change one of its gene.
+  # Help maintain diversity within the population and prevent premature convergence.
+  # @param [(Object | Float)[][]] ranges - The available ranges to mutate from for all genes. ranges.lenght must equals genes.length
+  # @param [Boolean] sampleFromRanges
+  #                  If true:  take one of the available values for a given range
+  #                  if false: take a random floating value between ranges[i][0] and ranges[i][1]
+  def mutate(ranges, sample_from_ranges = false)
+    i = rand(0..(genes.length - 1))
+    @genes[i] = sample_from_ranges ? ranges[i].sample : rand(ranges[i][0]..ranges[i][1])
+  end
+end

lib/genetic/algorithm/fitness_recorder.rb

@@ -0,0 +1,49 @@
+# Record and display best individuals accross generations
+class Genetic::Algorithm::FitnessRecorder
+  attr_accessor :best_individual
+
+  def initialize
+    @best_individual = nil
+    @max_fitness = []
+    @max_overall_finess = []
+    @average_fitness = []
+  end
+
+  def record_generation(generation, population)
+    best_generation_individual = population.max_by(&:fitness)
+
+    # Save best individual across all generations
+    if best_generation_individual.fitness > (@best_individual&.fitness || -1e10)
+      @best_individual = best_generation_individual
+    end
+
+    # Record progress information
+    @max_fitness << best_generation_individual.fitness
+    @max_overall_finess << @best_individual.fitness
+    average = population.map(&:fitness).inject(:+) / population.length
+    @average_fitness << average
+
+    puts "Generation #{generation} completed."
+    puts "    Best overall fitness: #{@best_individual.fitness}"
+    puts "    Best population fitness: #{best_generation_individual.fitness}"
+    puts "    Average population fitness: #{average}"
+  end
+
+  def display_best_individual(shifts)
+    puts "\n"
+    puts "Result: Best overall individual fitness: #{@best_individual.fitness}"
+    puts "                                                     Shift\t->\tSelected employee:"
+    print_shift = ->(shift) { "[#{shift.start_at.localtime} - #{shift.end_at.localtime}]: #{shift.position.name}" }
+    print_employee = ->(employee) { "#{employee.profile.full_name} (#{employee.email})" }
+    puts shifts.each_with_index.map { |s, i| "#{print_shift[s[:shift]]}\t->\t#{print_employee[@best_individual.genes[i].user]}" }
+
+    # puts "#{@max_fitness.each_with_index.map { |_, i| i }},"
+    # puts "#{@max_fitness},"
+    # puts "#{@max_overall_finess},"
+    # puts "#{@average_fitness},"
+  end
+
+  def save_best_individual_genes
+    raise "not implemented".freeze
+  end
+end

test/genetic/algorithm/chromosome_test.rb

@@ -0,0 +1,49 @@
+require "test_helper"
+require "genetic/algorithm/chromosome"
+
+class Genetic::Algorithm::ChromosomeTest < Minitest::Test
+  def test_it_can_mutate_floats
+    20.times do
+      test_genes = Array.new(rand(1..20)) { rand(0..100) }
+      test_ranges = Array.new(test_genes.length) do |i|
+        el = test_genes[i].to_f
+        [rand(el - 50.0..el), rand(el..el + 50.0)]
+      end
+
+      chromosome = Genetic::Algorithm::Chromosome.new(fitness: nil, genes: test_genes.dup)
+      chromosome.mutate(test_ranges)
+
+      number_of_mutated_genes = 0
+      chromosome.genes.each_with_index do |el, i|
+        if el != test_genes[i]
+          number_of_mutated_genes += 1
+        end
+
+        assert(test_ranges[i][0] < el && el < test_ranges[i][1])
+      end
+      assert_equal(1, number_of_mutated_genes)
+    end
+  end
+
+  def test_it_can_mutate_with_data_range
+    test_ranges = [%w[male female], [18, 19, 20, 21, 22], ["🔥", "❄️", "🌎", "💨"]]
+    test_genes = Array.new(test_ranges.length) { |i| test_ranges[i][0] }
+
+    chromosome = Genetic::Algorithm::Chromosome.new(fitness: nil, genes: test_genes.dup)
+    20.times do |i| # Discrete mutations can sometimes return the same value
+      assert(false, "Unable to mutate") if i == 20
+      chromosome.mutate(test_ranges, true)
+      break if chromosome.genes != test_genes
+    end
+
+    number_of_mutated_genes = 0
+    chromosome.genes.each_with_index do |el, i|
+      if el != test_genes[i]
+        number_of_mutated_genes += 1
+      end
+
+      assert((test_ranges[i].include? el))
+    end
+    assert_equal(1, number_of_mutated_genes)
+  end
+end

test/genetic/algorithm/resolver_test.rb

@@ -2,10 +2,6 @@
 
 class Genetic::Algorithm::ResolverTest < Minitest::Test
   def test_that_it_has_a_version_number
-    refute_nil ::Genetic::Algorithm::Resolver::VERSION
-  end
-
-  def test_it_does_something_useful
-    assert false
+    refute_nil Genetic::Algorithm::VERSION
   end
 end

test/test_helper.rb

@@ -1,4 +1,4 @@
 $LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
-require "genetic/algorithm/resolver"
+require "genetic/algorithm"
 
 require "minitest/autorun"