(#3) Introduce biased uniform cross-over operator for BRKGA

Author: jbytecode

src/randomkeyga.jl

@@ -39,6 +39,17 @@ function onepoint_crossover(ch::Chromosome, ch2::Chromosome)::Chromosome
     return Chromosome(vals1)
 end
 
+function uniform_crossover(elite::Chromosome, other::Chromosome; alpha::Float64 = 0.7)::Chromosome
+    L = length(elite.values)
+    vals1 = [rand() < alpha ? elite.values[i] : other.values[i] for i in 1:L]
+    return Chromosome(vals1)
+end
+
+function create_mutant(len::Int)::Chromosome
+    return Chromosome(rand(len), Inf64)
+end
+
+
 function random_mutation(ch::Chromosome)::Chromosome
     luckyindex = rand(1:length(ch.values))
     newch = Chromosome(copy(ch.values))

test/testrandomkeyga.jl

@@ -1,5 +1,28 @@
 @testset "Random Key Genetic Algorithm" verbose = true begin
 
+    @testset "Uniform Biased Crossover" begin
+        elite = Chromosome([0.1, 0.2, 0.3, 0.4, 0.5])
+        other = Chromosome([0.5, 0.4, 0.3, 0.2, 0.1])
+        alpha = 0.7
+
+        offspring = OperationsResearchModels.RandomKeyGA.uniform_crossover(elite, other; alpha)
+
+        @test length(offspring.values) == length(elite.values)
+        for i in 1:length(elite.values)
+            @test offspring.values[i] == elite.values[i] || offspring.values[i] == other.values[i]
+        end
+    end
+
+    @testset "Create Mutant" begin
+        len = 5
+        mutant = OperationsResearchModels.RandomKeyGA.create_mutant(len)
+
+        @test length(mutant.values) == len
+        for val in mutant.values
+            @test 0.0 <= val <= 1.0
+        end
+    end
+
     @testset "Example with chsize = 5" begin
 
         # Correct order is 1 2 3 4 5